归类了 OJ，整理了一下

XSM OJ 重庆小码王集团OJ/小码君的上学之路6.cpp

@@ -0,0 +1,47 @@
+#include <algorithm>
+#include <iostream>
+#include <iomanip>
+#include <cstring>
+#include <cstdio>
+#include <stack>
+#include <ctime>
+#include <cmath>
+#include <queue>
+typedef long long l;
+typedef double d;
+typedef char c;
+using namespace std;
+bool vis[600][600];
+int n,m,t;
+int sx,sy,fx,fy;
+int x,y;
+int ans;
+int dx[4]={1,-1,0,0};
+int dy[4]={0,0,1,-1};
+void dfs(int x,int y){
+	if(x==fx && y==fy){
+		ans++;
+		return;
+	}
+	for(int i=0;i<4;i++){
+		int nx=x+dx[i];
+		int ny=y+dy[i];
+		if(vis[nx][ny]==0 && nx>=1 && nx<=n && ny>=1 && ny<=m){
+			vis[nx][ny]=1;
+			dfs(nx,ny);
+			vis[nx][ny]=0;
+		}
+	}
+}
+int main(){
+	cin >>n>>m>>t;
+	cin >>sx>>sy>>fx>>fy;
+	for(int i=1;i<=t;i++){
+		cin >>x>>y;
+		vis[x][y]=1;
+	}
+	vis[sx][sy]=1;
+	dfs(sx,sy);
+	cout <<ans;
+	return 0;
+}