Section7-10. 경로탐색 (인접행렬, DFS)

Section07/경로탐색_인접행렬.java

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+package 인프런.Section07;
+
+import java.util.Scanner;
+
+public class 경로탐색_인접행렬 {
+
+    static int[][] graph;
+    static int n, m, answer = 0;
+    static int[] check;
+
+    public void DFS(int v) {
+        if(v == n) answer++;
+        else {
+            for(int i = 1; i <= n; i++) {
+                if(graph[v][i] == 1 && check[i] == 0) {
+                    check[i] = 1;
+                    DFS(i);
+                    check[i] = 0; //백트래킹 할때 check 한 거 다시 풀기
+                }
+            }
+        }
+
+    }
+
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+
+        경로탐색_인접행렬 t = new 경로탐색_인접행렬();
+
+        n = scanner.nextInt();
+        m = scanner.nextInt();
+
+        graph = new int[n+1][n+1];
+        check = new int[n+1];
+
+        for(int i = 0; i < m; i++) {
+            int a = scanner.nextInt();
+            int b = scanner.nextInt();
+            t.graph[a][b] = 1;
+        }
+        check[1] = 1;
+        t.DFS(1);
+        System.out.print(answer);
+    }
+}