Format source code (#150)

.clang-format

@@ -0,0 +1,14 @@
+---
+BasedOnStyle: Google
+IndentWidth: 4
+ColumnLimit: 120
+
+---
+Language: Cpp
+AllowShortBlocksOnASingleLine: false
+AllowShortIfStatementsOnASingleLine: false
+AllowShortLoopsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: Inline
+
+---
+Language: Java

.github/workflows/main.yml

@@ -0,0 +1,13 @@
+name: clang-format
+
+on: [push]
+
+jobs:
+  check-clang-format:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: run clang-format
+      run: |
+        source_files=$(find . -type f -name "*.cpp" -o -name "*.h" -o  -name "*.java")
+        diff -u <(cat $source_files) <(clang-format $source_files)

cpp/backtrack/mis.cpp

@@ -4,12 +4,14 @@ using namespace std;
 #ifdef _MSC_VER
 int __builtin_ctzll(unsigned long long x) {
     int bit = 0;
-    while (bit < 64 && (x & (1LL << bit)) == 0) ++bit;
+    while (bit < 64 && (x & (1LL << bit)) == 0)
+        ++bit;
     return bit;
 }
 int __builtin_popcountll(unsigned long long x) {
     int bits = 0;
-    for (; x; x &= x - 1, ++bits);
+    for (; x; x &= x - 1, ++bits)
+        ;
     return bits;
 }
 #endif

cpp/combinatorics/enumerating_combinations.cpp

@@ -18,7 +18,8 @@ bool next_combination(vector<int> &comb, int n) {
 int main() {
     vector<int> comb{0, 1, 2};
     do {
-        for (int v : comb) cout << v + 1 << " ";
+        for (int v : comb)
+            cout << v + 1 << " ";
         cout << endl;
     } while (next_combination(comb, 5));
 }

cpp/geometry/angle_area_orientation_sort_rotation_perpendicular.cpp

@@ -21,7 +21,7 @@ ll double_signed_area(const vector<int> &x, const vector<int> &y) {
     int n = x.size();
     ll area = 0;
     for (int i = 0, j = n - 1; i < n; j = i++) {
-        area += (ll) (x[i] - x[j]) * (y[i] + y[j]); // area += (long) x[i] * y[j] - (long) x[j] * y[i];
+        area += (ll)(x[i] - x[j]) * (y[i] + y[j]);  // area += (long) x[i] * y[j] - (long) x[j] * y[i];
     }
     return area;
 }
@@ -50,10 +50,12 @@ struct Point {
     bool operator<(const Point &o) const {
         bool up1 = y > 0 || (y == 0 && x >= 0);
         bool up2 = o.y > 0 || (o.y == 0 && o.x >= 0);
-        if (up1 != up2) return up1;
-        ll cmp = (ll) o.x * y - (ll) o.y * x;
-        if (cmp != 0) return cmp < 0;
-        return (ll) x * x + (ll) y * y < (ll) o.x * o.x + (ll) o.y * o.y;
+        if (up1 != up2)
+            return up1;
+        ll cmp = (ll)o.x * y - (ll)o.y * x;
+        if (cmp != 0)
+            return cmp < 0;
+        return (ll)x * x + (ll)y * y < (ll)o.x * o.x + (ll)o.y * o.y;
         // return atan2(y, x) < atan2(o.y, o.x);
     }
 };
@@ -71,5 +73,4 @@ Line perpendicular(Line line, ll x, ll y) {
 }
 
 // usage example
-int main() {
-}
+int main() {}

cpp/geometry/convex_hull.cpp

@@ -9,8 +9,8 @@ struct point {
 };
 
 bool isNotRightTurn(const point &a, const point &b, const point &c) {
-    long long cross = (long long) (a.x - b.x) * (c.y - b.y) - (long long) (a.y - b.y) * (c.x - b.x);
-    long long dot = (long long) (a.x - b.x) * (c.x - b.x) + (long long) (a.y - b.y) * (c.y - b.y);
+    long long cross = (long long)(a.x - b.x) * (c.y - b.y) - (long long)(a.y - b.y) * (c.x - b.x);
+    long long dot = (long long)(a.x - b.x) * (c.x - b.x) + (long long)(a.y - b.y) * (c.y - b.y);
     return cross < 0 || (cross == 0 && dot <= 0);
 }
 
@@ -30,13 +30,9 @@ vector<point> convex_hull(vector<point> points) {
 
 // usage example
 int main() {
-    vector<point> hull1 = convex_hull({{0, 0},
-                                       {3, 0},
-                                       {0, 3},
-                                       {1, 1}});
+    vector<point> hull1 = convex_hull({{0, 0}, {3, 0}, {0, 3}, {1, 1}});
     cout << (3 == hull1.size()) << endl;
 
-    vector<point> hull2 = convex_hull({{0, 0},
-                                       {0, 0}});
+    vector<point> hull2 = convex_hull({{0, 0}, {0, 0}});
     cout << (1 == hull2.size()) << endl;
 }

cpp/geometry/diameter.cpp

@@ -56,9 +56,6 @@ double diameter(const vector<point> &p) {
 
 // usage example
 int main() {
-    double d = diameter({{0, 0},
-                         {3, 0},
-                         {0, 3},
-                         {1, 1}});
+    double d = diameter({{0, 0}, {3, 0}, {0, 3}, {1, 1}});
     cout << d << endl;
 }

cpp/geometry/dynamic_upper_envelope.cpp

@@ -22,7 +22,7 @@ struct LineContainer : multiset<Line, less<>> {
     // (for doubles, use inf = 1/.0, div(a,b) = a/b)
     const ll inf = numeric_limits<ll>::max();
 
-    ll div(ll a, ll b) { // floored division
+    ll div(ll a, ll b) {  // floored division
         return a / b - ((a ^ b) < 0 && a % b);
     }
 
@@ -31,15 +31,19 @@ struct LineContainer : multiset<Line, less<>> {
             x->p = inf;
             return false;
         }
-        if (x->a == y->a) x->p = x->b > y->b ? inf : -inf;
-        else x->p = div(y->b - x->b, x->a - y->a);
+        if (x->a == y->a)
+            x->p = x->b > y->b ? inf : -inf;
+        else
+            x->p = div(y->b - x->b, x->a - y->a);
         return x->p >= y->p;
     }
 
     void add_line(ll a, ll b) {
         auto z = insert({a, b, 0}), y = z++, x = y;
-        while (isect(y, z)) z = erase(z);
-        if (x != begin() && isect(--x, y)) isect(x, erase(y));
+        while (isect(y, z))
+            z = erase(z);
+        if (x != begin() && isect(--x, y))
+            isect(x, erase(y));
         while ((y = x) != begin() && (--x)->p >= y->p)
             isect(x, erase(y));
     }

cpp/geometry/find_segments_intersection.cpp

@@ -18,9 +18,7 @@ struct segment {
     pii a, b;
     int id;
 
-    segment(pii a, pii b, int id) :
-            a(std::move(a)), b(std::move(b)), id(id) {
-    }
+    segment(pii a, pii b, int id) : a(std::move(a)), b(std::move(b)), id(id) {}
 
     bool operator<(const segment &o) const {
         if (a.first < o.a.first) {

cpp/geometry/li_chao_tree.cpp

@@ -9,9 +9,7 @@ using T = long long;
 struct Line {
     T a, d;
 
-    T eval(T x) {
-        return a * x + d;
-    }
+    T eval(T x) { return a * x + d; }
 };
 
 struct Node {
@@ -63,17 +61,11 @@ struct LiChaoTree {
     T maxx;
     Node *root;
 
-    LiChaoTree(T minx, T maxx) : minx(minx), maxx(maxx) {
-        root = new Node({0, numeric_limits<T>::max() / 2});
-    }
+    LiChaoTree(T minx, T maxx) : minx(minx), maxx(maxx) { root = new Node({0, numeric_limits<T>::max() / 2}); }
 
-    void add_line(Line line) {
-        root->add_line(line, minx, maxx + 1);
-    }
+    void add_line(Line line) { root->add_line(line, minx, maxx + 1); }
 
-    T get_min(T x) {
-        return root->get_min(x, minx, maxx + 1);
-    }
+    T get_min(T x) { return root->get_min(x, minx, maxx + 1); }
 };
 
 // usage example

cpp/geometry/point_classification.cpp

@@ -4,9 +4,7 @@ using namespace std;
 
 using ll = long long;
 
-enum class Position {
-    Left, Right, Behind, Beyond, Origin, Destionation, Between
-};
+enum class Position { Left, Right, Behind, Beyond, Origin, Destionation, Between };
 
 // Classifies position of point p against vector a
 Position classify(ll px, ll py, ll ax, ll ay) {
@@ -33,5 +31,4 @@ Position classify(ll px, ll py, ll ax, ll ay) {
 }
 
 // usage example
-int main() {
-}
+int main() {}

cpp/geometry/point_in_polygon.cpp

@@ -9,19 +9,18 @@ int pointInPolygon(int qx, int qy, const vector<int> &x, const vector<int> &y) {
     int cnt = 0;
     for (int i = 0, j = n - 1; i < n; j = i++) {
         if (y[i] == qy && (x[i] == qx || (y[j] == qy && (x[i] <= qx || x[j] <= qx) && (x[i] >= qx || x[j] >= qx))))
-            return 0; // boundary
+            return 0;  // boundary
         if ((y[i] > qy) != (y[j] > qy)) {
-            ll det = ((ll) x[i] - qx) * ((ll) y[j] - qy) - ((ll) x[j] - qx) * ((ll) y[i] - qy);
+            ll det = ((ll)x[i] - qx) * ((ll)y[j] - qy) - ((ll)x[j] - qx) * ((ll)y[i] - qy);
             if (det == 0)
-                return 0; // boundary
+                return 0;  // boundary
             if ((det > 0) != (y[j] > y[i]))
                 ++cnt;
         }
     }
     return cnt % 2 == 0 ? -1 /* exterior */ : 1 /* interior */;
 }
 
-
 // usage example
 int main() {
     vector<int> x{0, 0, 2, 2};

cpp/geometry/point_to_segment_distance.cpp

@@ -19,15 +19,14 @@ double point_to_segment_distance(int x, int y, int x1, int y1, int x2, int y2) {
         return fastHypot(px, py);
     if (dotProduct >= squaredLength)
         return fastHypot(px - dx, py - dy);
-    double q = (double) dotProduct / squaredLength;
+    double q = (double)dotProduct / squaredLength;
     return fastHypot(px - q * dx, py - q * dy);
 }
 
 double point_to_line_distance(ll x, ll y, ll a, ll b, ll c) {
     return abs(a * x + b * y + c) / fastHypot(a, b);
 }
 
-
 // usage example
 int main() {
     cout << fixed << setprecision(10);

cpp/geometry/segments_intersection.cpp

@@ -1,4 +1,5 @@
 #include <bits/stdc++.h>
+
 #include <optional>
 
 using namespace std;
@@ -14,8 +15,8 @@ bool is_cross_intersect(ll x1, ll y1, ll x2, ll y2, ll x3, ll y3, ll x4, ll y4)
 }
 
 bool is_cross_or_touch_intersect(ll x1, ll y1, ll x2, ll y2, ll x3, ll y3, ll x4, ll y4) {
-    if (max(x1, x2) < min(x3, x4) || max(x3, x4) < min(x1, x2)
-        || max(y1, y2) < min(y3, y4) || max(y3, y4) < min(y1, y2))
+    if (max(x1, x2) < min(x3, x4) || max(x3, x4) < min(x1, x2) || max(y1, y2) < min(y3, y4) ||
+        max(y3, y4) < min(y1, y2))
         return false;
     ll z1 = (x2 - x1) * (y3 - y1) - (y2 - y1) * (x3 - x1);
     ll z2 = (x2 - x1) * (y4 - y1) - (y2 - y1) * (x4 - x1);
@@ -34,17 +35,17 @@ optional<pair<double, double>> get_lines_intersection(ll x1, ll y1, ll x2, ll y2
     ll det = a1 * b2 - a2 * b1;
     if (det == 0)
         return {};
-    double x = -(c1 * b2 - c2 * b1) / (double) det;
-    double y = -(a1 * c2 - a2 * c1) / (double) det;
+    double x = -(c1 * b2 - c2 * b1) / (double)det;
+    double y = -(a1 * c2 - a2 * c1) / (double)det;
     return optional{make_pair(x, y)};
 }
 
 // usage example
 int main() {
     optional<pair<double, double>> intersection = get_lines_intersection(0, 0, 4, 2, 2, -1, 2, 5);
-    cout << (bool) intersection << endl;
+    cout << (bool)intersection << endl;
     cout << intersection->first << " " << intersection->second << endl;
 
     optional<pair<double, double>> no_intersection = get_lines_intersection(0, 0, 0, 1, 1, 0, 1, 1);
-    cout << (bool) no_intersection << endl;
+    cout << (bool)no_intersection << endl;
 }

cpp/graphs/cycle_detection.cpp

@@ -24,7 +24,8 @@ vector<int> find_cycle(const vector<vector<int>> &graph) {
     vector<int> color(n);
     vector<int> next(n);
     for (int u = 0; u < n; u++) {
-        if (color[u] != 0) continue;
+        if (color[u] != 0)
+            continue;
         int cycleStart = dfs(graph, u, color, next);
         if (cycleStart != -1) {
             vector<int> cycle;
@@ -41,17 +42,14 @@ vector<int> find_cycle(const vector<vector<int>> &graph) {
 
 // usage example
 int main() {
-    vector<vector<int>> graph{{1},
-                              {2},
-                              {0}};
+    vector<vector<int>> graph{{1}, {2}, {0}};
     auto cycle = find_cycle(graph);
     cout << cycle.size() << endl;
-    for (int x:cycle) cout << x << " ";
+    for (int x : cycle)
+        cout << x << " ";
     cout << endl;
 
-    graph = {{1},
-             {2},
-             {}};
+    graph = {{1}, {2}, {}};
     cycle = find_cycle(graph);
     cout << cycle.size() << endl;
 }

cpp/graphs/dfs/strongly_connected_components.cpp

@@ -50,26 +50,26 @@ vector<vector<int>> scc_graph(const vector<vector<int>> &graph, const vector<vec
     unordered_set<long long> edges;
     for (int u = 0; u < graph.size(); u++)
         for (int v : graph[u])
-            if (comp[u] != comp[v] && edges.insert(((long long) comp[u] << 32) + comp[v]).second)
+            if (comp[u] != comp[v] && edges.insert(((long long)comp[u] << 32) + comp[v]).second)
                 g[comp[u]].push_back(comp[v]);
     return g;
 }
 
 // usage example
 int main() {
-    vector<vector<int>> graph = {{1},
-                                 {0},
-                                 {0, 1}};
+    vector<vector<int>> graph = {{1}, {0}, {0, 1}};
 
     vector<vector<int>> components = scc(graph);
-    for (auto &component: components) {
-        for (int v:component) cout << v << " ";
+    for (auto &component : components) {
+        for (int v : component)
+            cout << v << " ";
         cout << endl;
     }
 
     vector<vector<int>> sg = scc_graph(graph, components);
-    for (auto &a: sg) {
-        for (int v : a) cout << v << " ";
+    for (auto &a : sg) {
+        for (int v : a)
+            cout << v << " ";
         cout << endl;
     }
 }

cpp/graphs/dfs/topological_sort.cpp

@@ -25,12 +25,11 @@ vector<int> topological_sort(const vector<vector<int>> &graph) {
 
 // usage example
 int main() {
-    vector<vector<int>> g = {{0},
-                             {},
-                             {0, 1}};
+    vector<vector<int>> g = {{0}, {}, {0, 1}};
 
     vector<int> order = topological_sort(g);
 
-    for (int v : order) cout << v << " ";
+    for (int v : order)
+        cout << v << " ";
     cout << endl;
 }

cpp/graphs/flows/global_min_cut_stoer_wagner.cpp

@@ -47,12 +47,10 @@ pair<int, vector<int>> min_cut(vector<vector<int>> &cap) {
 
 // usage example
 int main() {
-    vector<vector<int>> capacity{{0, 1, 1, 0},
-                                 {1, 0, 1, 1},
-                                 {1, 1, 0, 1},
-                                 {0, 1, 1, 0}};
-    auto[cap, cut] = min_cut(capacity);
+    vector<vector<int>> capacity{{0, 1, 1, 0}, {1, 0, 1, 1}, {1, 1, 0, 1}, {0, 1, 1, 0}};
+    auto [cap, cut] = min_cut(capacity);
     cout << cap << endl;
-    for (int v:cut) cout << v << " ";
+    for (int v : cut)
+        cout << v << " ";
     cout << endl;
 }