题目
代码
#include <bits/stdc++.h>
using namespace std;
int g[5][5];
int dx[] = {0, 0, -1, 1}, dy[] = {-1, 1, 0, 0};
int ans;
void dfs(int x, int y, int t)
{g[x][y] = t;if (t >= 16){ans++;g[x][y] = 0;return;}for (int i = 0; i < 4; i++){int nx = x + dx[i], ny = y + dy[i];if (nx < 1 || ny < 1 || nx > 4 || ny > 4)continue;if (g[nx][ny])continue;dfs(nx, ny, t + 1);}g[x][y] = 0;
}
int main()
{for (int i = 1; i <= 4; i++){for (int j = 1; j <= 4; j++)dfs(i, j, 1);}cout << ans;return 0;
}