Merge pull request #35 from AlgoLeadMe/9-SeongHoonC

9-SeongHoonC

SeongHoonC/README.md

@@ -10,4 +10,5 @@
 | 6차시 | 2024.02.05 | 큐/스택 | <a href="https://school.programmers.co.kr/learn/courses/30/lessons/42587"></a> | https://github.com/AlgoLeadMe/AlgoLeadMe-6/pull/20 |
 | 7차시 | 2024.02.08 | DP | <a href="https://www.acmicpc.net/problem/1932"></a> | https://github.com/AlgoLeadMe/AlgoLeadMe-6/pull/23 |
 | 8차시 | 2024.02.14 | 정렬 | <a href="https://www.acmicpc.net/problem/18870"></a> | https://github.com/AlgoLeadMe/AlgoLeadMe-6/pull/26 |
+| 9차시 | 2024.02.21 | bfs | <a href="https://www.acmicpc.net/problem/21736"></a> | https://github.com/AlgoLeadMe/AlgoLeadMe-6/pull/35 |
 ---

SeongHoonC/bfs/헌내기는 친구가 필요해.kt

@@ -0,0 +1,58 @@
+import java.io.BufferedReader
+import java.io.InputStreamReader
+
+val dx = listOf(1, -1, 0, 0)
+val dy = listOf(0, 0, 1, -1)
+
+fun main() {
+    val br = BufferedReader(InputStreamReader(System.`in`))
+    val (n, m) = br.readLine().split(" ").map { it.toInt() }
+
+    // n * m graph
+    val graph = Array(n) { Array(m) { "" } }
+    var start: Pair<Int, Int> = Pair(-1, -1)
+    for (i in 0 until n) {
+        val line = br.readLine().toList().map { it.toString() }
+        for (j in line.indices) {
+            graph[i][j] = line[j]
+            if (line[j] == "I") {
+                start = Pair(i, j)
+            }
+        }
+    }
+
+    // n * m visited
+    val visited = Array(n) { Array(m) { false } }
+    visited[start.first][start.second] = true
+
+    // 큐 생성
+    val q = ArrayDeque<Pair<Int, Int>>()
+    q.add(start)
+
+    var count = 0
+
+    while (q.isNotEmpty()) {
+        val now = q.removeFirst()
+        for (i in 0..3) {
+            val nextX = now.first + dx[i]
+            val nextY = now.second + dy[i]
+
+            // 캠퍼스 밖을 나간다
+            if (nextX < 0 || nextY < 0 || nextX >= n || nextY >= m) {
+                continue
+            }
+            // 이미 방문했거나 벽은 못감
+            if (visited[nextX][nextY] || graph[nextX][nextY] == "X") {
+                continue
+            }
+            // 사람이면 친구하기
+            if (graph[nextX][nextY] == "P") {
+                count++
+            }
+            // 방문 표시 후 큐에 추가
+            visited[nextX][nextY] = true
+            q.add(Pair(nextX, nextY))
+        }
+    }
+    println(if (count > 0) count else "TT")
+}