对一个3*4方格进行深度优先搜索联通块，有一个缺点是有一种联通快搜索不到。
#include <iostream> #include <cmath> using namespace std; int m = 3, n = 4, sum = 0; int pic[3][4]; bool visit[3][4] = { false }; void dfs(int i, int j, int cnt) { if (i < 0 || i >= m || j < 0 || j >= n) { return; } if (visit[i][j] == true) { return; } // pic[i][j] = cnt; visit[i][j] = true; if (cnt == 5) { sum++; return; } for (int i2 = -1; i2 <= 1; i2++) { for (int j2 = -1; j2 <= 1; j2++) { int abs_ij = abs(i2) + abs(j2); if (abs_ij != 2 && abs_ij != 0 && !visit[i+i2][j+j2]) { // visit[i2][j2] = true; dfs(i + i2, j + j2, cnt + 1); visit[i+i2][j+j2] = false; } } } } int main() { for (int i = 0; i < m; i++) { for (int j = 0; j < n; j++) { pic[i][j] = 0; } } for (int i = 0; i < m; i++) { for (int j = 0; j < n; j++) { int cnt = 0; dfs(i, j, cnt + 1); } } cout << "sum: " << sum << endl; return 0; }