diff --git a/examples/aoc2024/day02/part1.jou b/examples/aoc2024/day02/part1.jou
new file mode 100644
index 00000000..2936c58d
--- /dev/null
+++ b/examples/aoc2024/day02/part1.jou
@@ -0,0 +1,66 @@
+import "stdlib/io.jou"
+import "stdlib/mem.jou"
+import "stdlib/math.jou"
+import "stdlib/str.jou"
+import "stdlib/ascii.jou"
+
+
+class Report:
+    data: int*
+    len: int
+
+    def free(self) -> None:
+        free(self->data)
+
+    def is_safe(self) -> bool:
+        inc = True
+        dec = True
+
+        for i = 0; i < self->len - 1; i++:
+            d = self->data[i+1] - self->data[i]
+
+            if d <= 0:
+                inc = False
+            if d >= 0:
+                dec = False
+
+            if not (1 <= abs(d) and abs(d) <= 3):
+                return False
+
+        return inc or dec
+
+
+# mutates the line in-place through split_by_ascii_whitespace()
+def parse_report(line: byte*) -> Report:
+    words = split_by_ascii_whitespace(line)
+
+    n = 0
+    while words[n] != NULL:
+        n++
+
+    report = Report{len=n}
+    report.data = malloc(sizeof(report.data[0]) * n)
+    for i = 0; i < n; i++:
+        report.data[i] = atoi(words[i])
+
+    free(words)
+    return report
+
+
+def main() -> int:
+    f = fopen("sampleinput.txt", "r")
+    assert f != NULL
+
+    num_safe = 0
+
+    line: byte[1024]
+    while fgets(line, sizeof(line) as int, f) != NULL:
+        report = parse_report(line)
+        if report.is_safe():
+            num_safe++
+        report.free()
+
+    printf("%d\n", num_safe)  # Output: 2
+
+    fclose(f)
+    return 0
diff --git a/examples/aoc2024/day02/part2.jou b/examples/aoc2024/day02/part2.jou
new file mode 100644
index 00000000..779482b3
--- /dev/null
+++ b/examples/aoc2024/day02/part2.jou
@@ -0,0 +1,84 @@
+import "stdlib/io.jou"
+import "stdlib/mem.jou"
+import "stdlib/math.jou"
+import "stdlib/str.jou"
+import "stdlib/ascii.jou"
+
+
+class Report:
+    data: int*
+    len: int
+
+    def free(self) -> None:
+        free(self->data)
+
+    def is_safe(self) -> bool:
+        inc = True
+        dec = True
+
+        for i = 0; i < self->len - 1; i++:
+            d = self->data[i+1] - self->data[i]
+
+            if d <= 0:
+                inc = False
+            if d >= 0:
+                dec = False
+
+            if not (1 <= abs(d) and abs(d) <= 3):
+                return False
+
+        return inc or dec
+
+    def pop(self, i: int) -> int:
+        bye = self->data[i]
+        memmove(&self->data[i], &self->data[i+1], sizeof(self->data[0]) * (--self->len - i))
+        return bye
+
+    def insert(self, i: int, value: int) -> None:
+        # assumes there is enough room in the array and no reallocation is needed
+        memmove(&self->data[i+1], &self->data[i], sizeof(self->data[0]) * (self->len++ - i))
+        self->data[i] = value
+
+
+# mutates the line in-place through split_by_ascii_whitespace()
+def parse_report(line: byte*) -> Report:
+    words = split_by_ascii_whitespace(line)
+
+    n = 0
+    while words[n] != NULL:
+        n++
+
+    report = Report{len=n}
+    report.data = malloc(sizeof(report.data[0]) * n)
+    for i = 0; i < n; i++:
+        report.data[i] = atoi(words[i])
+
+    free(words)
+    return report
+
+
+def main() -> int:
+    f = fopen("sampleinput.txt", "r")
+    assert f != NULL
+
+    num_safe = 0
+
+    line: byte[1024]
+    while fgets(line, sizeof(line) as int, f) != NULL:
+        report = parse_report(line)
+        if report.is_safe():
+            num_safe++
+        else:
+            for i = 0; i < report.len; i++:
+                temp_missing = report.pop(i)
+                if report.is_safe():
+                    num_safe++
+                    break
+                report.insert(i, temp_missing)
+
+        report.free()
+
+    printf("%d\n", num_safe)  # Output: 4
+
+    fclose(f)
+    return 0
diff --git a/examples/aoc2024/day02/sampleinput.txt b/examples/aoc2024/day02/sampleinput.txt
new file mode 100644
index 00000000..b49c10d7
--- /dev/null
+++ b/examples/aoc2024/day02/sampleinput.txt
@@ -0,0 +1,6 @@
+7 6 4 2 1
+1 2 7 8 9
+9 7 6 2 1
+1 3 2 4 5
+8 6 4 4 1
+1 3 6 7 9
diff --git a/examples/aoc2024/day03/part1.jou b/examples/aoc2024/day03/part1.jou
new file mode 100644
index 00000000..218149da
--- /dev/null
+++ b/examples/aoc2024/day03/part1.jou
@@ -0,0 +1,59 @@
+import "stdlib/str.jou"
+import "stdlib/io.jou"
+import "stdlib/mem.jou"
+import "stdlib/ascii.jou"
+
+
+# Moves s in-place beyond used characters. Returns 0 on failure.
+def parse_int(s: byte**) -> int:
+    result = 0
+    while is_ascii_digit(**s):
+        result *= 10
+        result += (*(*s)++ - '0')
+    return result
+
+
+# Returns 0 if doesn't match.
+def parse_mul(s: byte*) -> int:
+    if not starts_with(s, "mul("):
+        return 0
+    s = &s[4]
+
+    a = parse_int(&s)
+    if *s++ != ',':
+        return 0
+    b = parse_int(&s)
+    if *s++ != ')':
+        return 0
+    return a*b
+
+
+def main() -> int:
+    max_size = 100000
+    big_string: byte* = malloc(max_size)
+
+    f = fopen("sampleinput1.txt", "r")
+    assert f != NULL
+
+    i = 0
+    while True:
+        c = fgetc(f)
+        EOF = -1  # TODO: belongs to stdlib
+        if c == EOF:
+            break
+        assert i < max_size
+        big_string[i++] = c as byte
+
+    assert i < max_size
+    big_string[i] = '\0'
+
+    fclose(f)
+
+    result = 0 as long
+    s = big_string
+    while *s != '\0':
+        result += parse_mul(s++)
+
+    free(big_string)
+    printf("%d\n", result)  # Output: 161
+    return 0
diff --git a/examples/aoc2024/day03/part2.jou b/examples/aoc2024/day03/part2.jou
new file mode 100644
index 00000000..8e94d93a
--- /dev/null
+++ b/examples/aoc2024/day03/part2.jou
@@ -0,0 +1,77 @@
+import "stdlib/str.jou"
+import "stdlib/io.jou"
+import "stdlib/mem.jou"
+import "stdlib/ascii.jou"
+
+
+# Moves s in-place beyond used characters. Returns 0 on failure.
+def parse_int(s: byte**) -> int:
+    result = 0
+    while is_ascii_digit(**s):
+        result *= 10
+        result += (*(*s)++ - '0')
+    return result
+
+
+# Returns 0 if doesn't match.
+def parse_mul(s: byte*) -> int:
+    if not starts_with(s, "mul("):
+        return 0
+    s = &s[4]
+
+    a = parse_int(&s)
+    if *s++ != ',':
+        return 0
+    b = parse_int(&s)
+    if *s++ != ')':
+        return 0
+    return a*b
+
+
+def remove_disabled_sections(s: byte*) -> None:
+    while True:
+        dont = strstr(s, "don't()")
+        if dont == NULL:
+            break
+
+        do = strstr(dont, "do()")
+        if do == NULL:
+            # disable to end
+            *dont = '\0'
+        else:
+            # delete dont()...do()
+            do_end = &do[4]
+            memmove(dont, do_end, strlen(do_end) + 1)
+
+
+def main() -> int:
+    max_size = 100000
+    big_string: byte* = malloc(max_size)
+
+    f = fopen("sampleinput2.txt", "r")
+    assert f != NULL
+
+    i = 0
+    while True:
+        c = fgetc(f)
+        EOF = -1  # TODO: belongs to stdlib
+        if c == EOF:
+            break
+        assert i < max_size
+        big_string[i++] = c as byte
+
+    assert i < max_size
+    big_string[i] = '\0'
+
+    fclose(f)
+
+    remove_disabled_sections(big_string)
+
+    result = 0 as long
+    s = big_string
+    while *s != '\0':
+        result += parse_mul(s++)
+
+    free(big_string)
+    printf("%d\n", result)  # Output: 48
+    return 0
diff --git a/examples/aoc2024/day03/sampleinput1.txt b/examples/aoc2024/day03/sampleinput1.txt
new file mode 100644
index 00000000..f274bdae
--- /dev/null
+++ b/examples/aoc2024/day03/sampleinput1.txt
@@ -0,0 +1 @@
+xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))
diff --git a/examples/aoc2024/day03/sampleinput2.txt b/examples/aoc2024/day03/sampleinput2.txt
new file mode 100644
index 00000000..30032cbe
--- /dev/null
+++ b/examples/aoc2024/day03/sampleinput2.txt
@@ -0,0 +1 @@
+xmul(2,4)&mul[3,7]!^don't()_mul(5,5)+mul(32,64](mul(11,8)undo()?mul(8,5))
diff --git a/examples/aoc2024/day04/part1.jou b/examples/aoc2024/day04/part1.jou
new file mode 100644
index 00000000..4243c0d3
--- /dev/null
+++ b/examples/aoc2024/day04/part1.jou
@@ -0,0 +1,57 @@
+import "../../aoc2023/grid.jou"
+import "stdlib/str.jou"
+import "stdlib/mem.jou"
+import "stdlib/io.jou"
+
+
+def count_in_string(s: byte*) -> int:
+    n = 0
+    for i = 0; s[i] != '\0'; i++:
+        if starts_with(&s[i], "XMAS") or starts_with(&s[i], "SAMX"):
+            n++
+    return n
+
+
+def count_diagonals(grid: Grid*) -> int:
+    big_size = grid->width + grid->height + 69
+    temp_string: byte* = malloc(big_size)
+    assert temp_string != NULL
+
+    result = 0
+
+    for c = -big_size; c <= big_size; c++:
+        # diagonals like /, along lines whose equation is y = x + c
+        p = temp_string
+        for x = 0; x < grid->width; x++:
+            y = x + c
+            if 0 <= y and y < grid->height:
+                *p++ = grid->get([x, y])
+        *p = '\0'
+        result += count_in_string(temp_string)
+
+        # diagonals like \, along lines whose equation is y = -x + c
+        p = temp_string
+        for x = 0; x < grid->width; x++:
+            y = -x + c
+            if 0 <= y and y < grid->height:
+                *p++ = grid->get([x, y])
+        *p = '\0'
+        result += count_in_string(temp_string)
+
+    free(temp_string)
+    return result
+
+
+def main() -> int:
+    f = fopen("sampleinput.txt", "r")
+    grid = read_grid_from_file(f)
+    fclose(f)
+
+    horizontal = count_in_string(grid.data)
+    grid.transpose()
+    vertical = count_in_string(grid.data)
+    diagonal = count_diagonals(&grid)
+    printf("%d\n", horizontal + vertical + diagonal)  # Output: 18
+
+    free(grid.data)
+    return 0
diff --git a/examples/aoc2024/day04/part2.jou b/examples/aoc2024/day04/part2.jou
new file mode 100644
index 00000000..9ff77eb3
--- /dev/null
+++ b/examples/aoc2024/day04/part2.jou
@@ -0,0 +1,46 @@
+import "../../aoc2023/grid.jou"
+import "stdlib/io.jou"
+import "stdlib/mem.jou"
+
+
+# Count how many times template matches grid
+# "." in template can be any character
+def count_template(grid: Grid*, template: Grid*) -> int:
+    count = 0
+    for ox = 0; ox <= grid->width - template->width; ox++:
+        for oy = 0; oy <= grid->height - template->height; oy++:
+            all_match = True
+            for x = 0; x < template->width; x++:
+                for y = 0; y < template->height; y++:
+                    grid_byte = grid->get([ox + x, oy + y])
+                    template_byte = template->get([x, y])
+                    if grid_byte != template_byte and template_byte != '.':
+                        all_match = False
+            if all_match:
+                count += 1
+    return count
+
+
+def main() -> int:
+    templates: Grid[10]
+    num_templates = 0
+
+    f = fopen("part2_templates.txt", "r")
+    while feof(f) == 0:
+        assert num_templates < sizeof(templates)/sizeof(templates[0])
+        templates[num_templates++] = read_grid_from_file(f)
+    fclose(f)
+
+    f = fopen("sampleinput.txt", "r")
+    grid = read_grid_from_file(f)
+    fclose(f)
+
+    result = 0
+    for i = 0; i < num_templates; i++:
+        result += count_template(&grid, &templates[i])
+    printf("%d\n", result)  # Output: 9
+
+    for i = 0; i < num_templates; i++:
+        free(templates[i].data)
+    free(grid.data)
+    return 0
diff --git a/examples/aoc2024/day04/part2_templates.txt b/examples/aoc2024/day04/part2_templates.txt
new file mode 100644
index 00000000..0d9a6fa0
--- /dev/null
+++ b/examples/aoc2024/day04/part2_templates.txt
@@ -0,0 +1,15 @@
+M.S
+.A.
+M.S
+
+S.S
+.A.
+M.M
+
+S.M
+.A.
+S.M
+
+M.M
+.A.
+S.S
diff --git a/examples/aoc2024/day04/sampleinput.txt b/examples/aoc2024/day04/sampleinput.txt
new file mode 100644
index 00000000..1f4eda20
--- /dev/null
+++ b/examples/aoc2024/day04/sampleinput.txt
@@ -0,0 +1,10 @@
+MMMSXXMASM
+MSAMXMSMSA
+AMXSXMAAMM
+MSAMASMSMX
+XMASAMXAMM
+XXAMMXXAMA
+SMSMSASXSS
+SAXAMASAAA
+MAMMMXMMMM
+MXMXAXMASX
diff --git a/examples/aoc2024/day05/part1.jou b/examples/aoc2024/day05/part1.jou
new file mode 100644
index 00000000..b9e8be3c
--- /dev/null
+++ b/examples/aoc2024/day05/part1.jou
@@ -0,0 +1,105 @@
+import "stdlib/io.jou"
+import "stdlib/mem.jou"
+import "stdlib/ascii.jou"
+import "stdlib/str.jou"
+
+
+def read_rules(file: FILE*, nrules: int*) -> int[2]*:
+    *nrules = 0
+
+    max_rules = 2000
+    rules: int[2]* = malloc(sizeof(rules[0]) * max_rules)
+    assert rules != NULL
+
+    line: byte[100]
+    while fgets(line, sizeof(line) as int, file) != NULL:
+        trim_ascii_whitespace(line)
+        if line[0] == '\0':
+            # This is the blank line that separates rules and jobs
+            return rules
+
+        rule: int[2]
+        r = sscanf(line, "%d|%d", &rule[0], &rule[1])
+        assert r == 2
+
+        assert *nrules < max_rules
+        rules[*nrules] = rule
+        ++*nrules
+
+    return rules
+
+
+# Each returned print job is terminated by -1
+def read_print_jobs(file: FILE*, njobs: int*) -> int[100]*:
+    *njobs = 0
+
+    max_jobs = 500
+    jobs: int[100]* = malloc(sizeof(jobs[0]) * max_jobs)
+    assert jobs != NULL
+
+    line: byte[100]
+    while fgets(line, sizeof(line) as int, file) != NULL:
+        job: int[100]
+        num_pages = 0
+
+        p: byte* = line
+        while True:
+            assert num_pages < sizeof(job)/sizeof(job[0])
+            job[num_pages++] = atoi(p)
+            p = strstr(p, ",")
+            if p == NULL:
+                break
+            p++  # skip comma
+
+        assert num_pages < sizeof(job)/sizeof(job[0])
+        job[num_pages] = -1
+
+        assert *njobs < max_jobs
+        jobs[(*njobs)++] = job
+
+    return jobs
+
+
+def find_page(job: int*, value: int) -> int:
+    for i = 0; job[i] != -1; i++:
+        if job[i] == value:
+            return i
+    return -1
+
+
+def job_is_valid(rules: int[2]*, nrules: int, job: int*) -> bool:
+    for i = 0; i < nrules; i++:
+        first_idx = find_page(job, rules[i][0])
+        second_idx = find_page(job, rules[i][1])
+        if first_idx != -1 and second_idx != -1 and first_idx >= second_idx:
+            return False
+    return True
+
+
+def main() -> int:
+    f = fopen("sampleinput.txt", "r")
+    assert f != NULL
+
+    nrules: int
+    rules = read_rules(f, &nrules)
+
+    njobs: int
+    jobs = read_print_jobs(f, &njobs)
+
+    fclose(f)
+
+    midsum = 0L
+    for i = 0; i < njobs; i++:
+        job = jobs[i]
+        if job_is_valid(rules, nrules, job):
+            n = 0
+            while job[n] != -1:
+                n++
+            assert n % 2 == 1
+            midsum += job[(n - 1) / 2]
+
+    printf("%d\n", midsum)  # Output: 143
+
+    free(rules)
+    free(jobs)
+    return 0
diff --git a/examples/aoc2024/day05/part2.jou b/examples/aoc2024/day05/part2.jou
new file mode 100644
index 00000000..aa8efa9d
--- /dev/null
+++ b/examples/aoc2024/day05/part2.jou
@@ -0,0 +1,127 @@
+import "stdlib/io.jou"
+import "stdlib/mem.jou"
+import "stdlib/ascii.jou"
+import "stdlib/str.jou"
+
+
+def read_rules(file: FILE*, nrules: int*) -> int[2]*:
+    *nrules = 0
+
+    max_rules = 2000
+    rules: int[2]* = malloc(sizeof(rules[0]) * max_rules)
+    assert rules != NULL
+
+    line: byte[100]
+    while fgets(line, sizeof(line) as int, file) != NULL:
+        trim_ascii_whitespace(line)
+        if line[0] == '\0':
+            # This is the blank line that separates rules and jobs
+            return rules
+
+        rule: int[2]
+        r = sscanf(line, "%d|%d", &rule[0], &rule[1])
+        assert r == 2
+
+        assert *nrules < max_rules
+        rules[*nrules] = rule
+        ++*nrules
+
+    return rules
+
+
+# Each returned print job is terminated by -1
+def read_print_jobs(file: FILE*, njobs: int*) -> int[100]*:
+    *njobs = 0
+
+    max_jobs = 500
+    jobs: int[100]* = malloc(sizeof(jobs[0]) * max_jobs)
+    assert jobs != NULL
+
+    line: byte[100]
+    while fgets(line, sizeof(line) as int, file) != NULL:
+        job: int[100]
+        num_pages = 0
+
+        p: byte* = line
+        while True:
+            assert num_pages < sizeof(job)/sizeof(job[0])
+            job[num_pages++] = atoi(p)
+            p = strstr(p, ",")
+            if p == NULL:
+                break
+            p++  # skip comma
+
+        assert num_pages < sizeof(job)/sizeof(job[0])
+        job[num_pages] = -1
+
+        assert *njobs < max_jobs
+        jobs[(*njobs)++] = job
+
+    return jobs
+
+
+def find_page(job: int*, value: int) -> int:
+    for i = 0; job[i] != -1; i++:
+        if job[i] == value:
+            return i
+    return -1
+
+
+def job_is_valid(rules: int[2]*, nrules: int, job: int*) -> bool:
+    for i = 0; i < nrules; i++:
+        first_idx = find_page(job, rules[i][0])
+        second_idx = find_page(job, rules[i][1])
+        if first_idx != -1 and second_idx != -1 and first_idx >= second_idx:
+            return False
+    return True
+
+
+def swap(a: int*, b: int*) -> None:
+    old_a = *a
+    *a = *b
+    *b = old_a
+
+
+def fix_job(rules: int[2]*, nrules: int, job: int*) -> None:
+    length = 0
+    while job[length] != -1:
+        length++
+
+    # super dumb, swap until it's ok
+    while not job_is_valid(rules, nrules, job):
+        for i = 0; i < nrules; i++:
+            rule = rules[i]
+            first_idx = find_page(job, rule[0])
+            second_idx = find_page(job, rule[1])
+            if first_idx != -1 and second_idx != -1 and first_idx >= second_idx:
+                swap(&job[first_idx], &job[second_idx])
+
+
+def main() -> int:
+    f = fopen("sampleinput.txt", "r")
+    assert f != NULL
+
+    nrules: int
+    rules = read_rules(f, &nrules)
+
+    njobs: int
+    jobs = read_print_jobs(f, &njobs)
+
+    fclose(f)
+
+    midsum = 0L
+    for i = 0; i < njobs; i++:
+        job = jobs[i]
+        if not job_is_valid(rules, nrules, job):
+            fix_job(rules, nrules, job)
+            n = 0
+            while job[n] != -1:
+                n++
+            assert n % 2 == 1
+            midsum += job[(n - 1) / 2]
+
+    printf("%d\n", midsum)  # Output: 123
+
+    free(rules)
+    free(jobs)
+    return 0
diff --git a/examples/aoc2024/day05/sampleinput.txt b/examples/aoc2024/day05/sampleinput.txt
new file mode 100644
index 00000000..9d146d67
--- /dev/null
+++ b/examples/aoc2024/day05/sampleinput.txt
@@ -0,0 +1,28 @@
+47|53
+97|13
+97|61
+97|47
+75|29
+61|13
+75|53
+29|13
+97|29
+53|29
+61|53
+97|53
+61|29
+47|13
+75|47
+97|75
+47|61
+75|61
+47|29
+75|13
+53|13
+
+75,47,61,53,29
+97,61,53,29,13
+75,29,13
+75,97,47,61,53
+61,13,29
+97,13,75,29,47
diff --git a/examples/aoc2024/day06/part1.jou b/examples/aoc2024/day06/part1.jou
new file mode 100644
index 00000000..e8c281be
--- /dev/null
+++ b/examples/aoc2024/day06/part1.jou
@@ -0,0 +1,29 @@
+import "../../aoc2023/grid.jou"
+import "stdlib/io.jou"
+import "stdlib/mem.jou"
+
+
+def main() -> int:
+    f = fopen("sampleinput.txt", "r")
+    grid = read_grid_from_file(f)
+    fclose(f)
+
+    pos = grid.find_first('^')
+    movement = [0, -1]  # up
+
+    while True:
+        grid.set(pos, 'X')
+
+        new_pos = [pos[0] + movement[0], pos[1] + movement[1]]
+        if not grid.is_in_bounds(new_pos):
+            break
+        elif grid.get(new_pos) == '#':
+            # turn right 90deg
+            movement = [-movement[1], movement[0]]
+        else:
+            pos = new_pos
+
+    printf("%d\n", grid.count('X'))  # Output: 41
+
+    free(grid.data)
+    return 0
diff --git a/examples/aoc2024/day06/part2.jou b/examples/aoc2024/day06/part2.jou
new file mode 100644
index 00000000..bebf84ba
--- /dev/null
+++ b/examples/aoc2024/day06/part2.jou
@@ -0,0 +1,56 @@
+import "../../aoc2023/grid.jou"
+import "stdlib/io.jou"
+import "stdlib/mem.jou"
+
+
+def we_gonna_get_stuck(grid: Grid*) -> bool:
+    # Order: [up, right, down, left] (rotates clockwise)
+    dx = [0, 1, 0, -1]
+    dy = [-1, 0, 1, 0]
+    visited = [grid->copy(), grid->copy(), grid->copy(), grid->copy()]
+
+    pos = grid->find_first('^')
+    movement_kind = 0
+    got_stuck = False
+
+    while True:
+        if visited[movement_kind].get(pos) == 'X':
+            # We saw the same exact move before.
+            got_stuck = True
+            break
+        visited[movement_kind].set(pos, 'X')
+
+        new_pos = [pos[0] + dx[movement_kind], pos[1] + dy[movement_kind]]
+        if not grid->is_in_bounds(new_pos):
+            break
+        elif grid->get(new_pos) == '#':
+            # turn right 90deg
+            movement_kind = (movement_kind + 1) % 4
+        else:
+            pos = new_pos
+
+    free(visited[0].data)
+    free(visited[1].data)
+    free(visited[2].data)
+    free(visited[3].data)
+    return got_stuck
+
+
+def main() -> int:
+    f = fopen("sampleinput.txt", "r")
+    grid = read_grid_from_file(f)
+    fclose(f)
+
+    counter = 0
+    for p = grid.data; *p != '\0'; p++:
+        if *p == '.':
+            # Place obstacle here
+            *p = '#'
+            if we_gonna_get_stuck(&grid):
+                counter++
+            *p = '.'
+
+    printf("%d\n", counter)  # Output: 6
+
+    free(grid.data)
+    return 0
diff --git a/examples/aoc2024/day06/sampleinput.txt b/examples/aoc2024/day06/sampleinput.txt
new file mode 100644
index 00000000..a4eb402c
--- /dev/null
+++ b/examples/aoc2024/day06/sampleinput.txt
@@ -0,0 +1,10 @@
+....#.....
+.........#
+..........
+..#.......
+.......#..
+..........
+.#..^.....
+........#.
+#.........
+......#...
diff --git a/examples/aoc2024/day07/part1.jou b/examples/aoc2024/day07/part1.jou
new file mode 100644
index 00000000..0326de65
--- /dev/null
+++ b/examples/aoc2024/day07/part1.jou
@@ -0,0 +1,79 @@
+import "stdlib/mem.jou"
+import "stdlib/io.jou"
+import "stdlib/str.jou"
+
+
+class Equation:
+    expected_result: long
+    values: long[100]
+    nvalues: int
+
+    def is_satisfiable(self) -> bool:
+        assert self->nvalues > 0
+        results: long* = malloc(sizeof(results[0]) * 1)
+        assert results != NULL
+        results[0] = self->values[0]
+        nresults = 1
+
+        for value = &self->values[1]; value < &self->values[self->nvalues]; value++:
+            if nresults == 0:
+                break
+
+            new_results: long* = malloc(sizeof(new_results[0]) * (nresults * 2))
+            assert new_results != NULL
+            new_nresults = 0
+
+            # Let's try plus
+            for i = 0; i < nresults; i++:
+                r = results[i] + (*value)
+                assert r >= results[i]
+                # if too big already, no way it will be ok later
+                if r <= self->expected_result:
+                    new_results[new_nresults++] = r
+
+            # Let's try multiplying
+            for i = 0; i < nresults; i++:
+                r = results[i] * (*value)
+                assert r >= results[i]
+                # if too big already, no way it will be ok later
+                if r <= self->expected_result:
+                    new_results[new_nresults++] = r
+
+            free(results)
+            results = new_results
+            nresults = new_nresults
+
+        found = False
+        for i = 0; i < nresults; i++:
+            if results[i] == self->expected_result:
+                found = True
+                break
+
+        free(results)
+        return found
+
+
+def main() -> int:
+    f = fopen("sampleinput.txt", "r")
+    assert f != NULL
+
+    result = 0L
+
+    line: byte[100]
+    while fgets(line, sizeof(line) as int, f) != NULL:
+        eq = Equation{expected_result = atoll(line)}
+
+        # Remaining numbers are always after a space
+        p = &line[0]
+        while strstr(p, " ") != NULL:
+            p = strstr(p, " ")
+            p++  # skip space
+            assert eq.nvalues < sizeof(eq.values)/sizeof(eq.values[0])
+            eq.values[eq.nvalues++] = atoll(p)
+
+        if eq.is_satisfiable():
+            result += eq.expected_result
+
+    fclose(f)
+    printf("%lld\n", result)  # Output: 3749
+    return 0
diff --git a/examples/aoc2024/day07/part2.jou b/examples/aoc2024/day07/part2.jou
new file mode 100644
index 00000000..42f35110
--- /dev/null
+++ b/examples/aoc2024/day07/part2.jou
@@ -0,0 +1,105 @@
+import "stdlib/mem.jou"
+import "stdlib/io.jou"
+import "stdlib/str.jou"
+
+
+# Example: length_of_a_number(69420) == 5
+def length_of_a_number(x: long) -> int:
+    assert x > 0
+    result = 0
+    while x != 0:
+        x /= 10
+        result++
+    return result
+
+
+# Example: concat(69, 420) == 69420
+def concat(a: long, b: long) -> long:
+    b_len = length_of_a_number(b)
+    while b_len --> 0:
+        a *= 10
+    return a + b
+
+
+class Equation:
+    expected_result: long
+    values: long[100]
+    nvalues: int
+
+    def is_satisfiable(self) -> bool:
+        assert self->nvalues > 0
+        results: long* = malloc(sizeof(results[0]) * 1)
+        assert results != NULL
+        results[0] = self->values[0]
+        nresults = 1
+
+        for value = &self->values[1]; value < &self->values[self->nvalues]; value++:
+            if nresults == 0:
+                break
+
+            new_results: long* = malloc(sizeof(new_results[0]) * (nresults * 3))
+            assert new_results != NULL
+            new_nresults = 0
+
+            # Let's try plus
+            for i = 0; i < nresults; i++:
+                r = results[i] + (*value)
+                assert r >= results[i]
+                # if too big already, no way it will be ok later
+                if r <= self->expected_result:
+                    new_results[new_nresults++] = r
+
+            # Let's try multiplying
+            for i = 0; i < nresults; i++:
+                r = results[i] * (*value)
+                assert r >= results[i]
+                # if too big already, no way it will be ok later
+                if r <= self->expected_result:
+                    new_results[new_nresults++] = r
+
+            # Let's try concatenating
+            for i = 0; i < nresults; i++:
+                r = concat(results[i], *value)
+                assert r >= results[i]
+                # if too big already, no way it will be ok later
+                if r <= self->expected_result:
+                    new_results[new_nresults++] = r
+
+            free(results)
+            results = new_results
+            nresults = new_nresults
+
+        found = False
+        for i = 0; i < nresults; i++:
+            if results[i] == self->expected_result:
+                found = True
+                break
+
+        free(results)
+        return found
+
+
+def main() -> int:
+    f = fopen("sampleinput.txt", "r")
+    assert f != NULL
+
+    result = 0L
+
+    line: byte[100]
+    while fgets(line, sizeof(line) as int, f) != NULL:
+        eq = Equation{expected_result = atoll(line)}
+
+        # Remaining numbers are always after a space
+        p = &line[0]
+        while strstr(p, " ") != NULL:
+            p = strstr(p, " ")
+            p++  # skip space
+            assert eq.nvalues < sizeof(eq.values)/sizeof(eq.values[0])
+            eq.values[eq.nvalues++] = atoll(p)
+
+        if eq.is_satisfiable():
+            result += eq.expected_result
+
+    fclose(f)
+    printf("%lld\n", result)  # Output: 11387
+    return 0
diff --git a/examples/aoc2024/day07/sampleinput.txt b/examples/aoc2024/day07/sampleinput.txt
new file mode 100644
index 00000000..fc6e099d
--- /dev/null
+++ b/examples/aoc2024/day07/sampleinput.txt
@@ -0,0 +1,9 @@
+190: 10 19
+3267: 81 40 27
+83: 17 5
+156: 15 6
+7290: 6 8 6 15
+161011: 16 10 13
+192: 17 8 14
+21037: 9 7 18 13
+292: 11 6 16 20