https://www.acwing.com/problem/content/97/
看了一下感觉可以暴力做，踩了一些坑终于过了。
#include<bits/stdc++.h> using namespace std; typedef long long ll; int cur; int set_ij(int u, int i, int j) { int cur = u; cur ^= 1 << (i * 5 + j); if(i - 1 >= 0) cur ^= 1 << ((i - 1) * 5 + j); if(j - 1 >= 0) cur ^= 1 << (i * 5 + j - 1); if(i + 1 < 5) cur ^= 1 << ((i + 1) * 5 + j); if(j + 1 < 5) cur ^= 1 << (i * 5 + j + 1); return cur; } char vis[1 << 25]; int Q[1 << 20], front, back; void bfs1() { vis[cur] = 0; front = 1; back = 0; Q[++back] = cur; while(front <= back) { int u = Q[front++]; if(vis[u] < 2) { for(int i = 0; i < 5; ++i) { for(int j = 0; j < 5; ++j) { int tmp = set_ij(u, i, j); if(vis[tmp] == -1) { vis[tmp] = vis[u] + 1; Q[++back] = tmp; } } } } } } char vis2[1 << 25]; int suc; void bfs2() { vis2[cur] = 0; front = 1; back = 0; Q[++back] = cur; while(front <= back) { int u = Q[front++]; if(vis2[u] < 4) { for(int i = 0; i < 5; ++i) { for(int j = 0; j < 5; ++j) { int tmp = set_ij(u, i, j); if(vis2[tmp] == -1) { vis2[tmp] = vis2[u] + 1; Q[++back] = tmp; } } } } } } int main() { #ifdef Yinku freopen("Yinku.in", "r", stdin); #endif // Yinku for(int i = 0; i < 5; ++i) { for(int j = 0; j < 5; ++j) { cur |= 1 << (i * 5 + j); } } memset(vis2, -1, sizeof(vis2)); bfs2(); int T; scanf("%d", &T); memset(vis, -1, sizeof(vis)); while(T--) { cur = 0; for(int i = 0; i < 5; ++i) { for(int j = 0; j < 5; ++j) { int tmp; scanf("%1d", &tmp); if(tmp) cur |= 1 << (i * 5 + j); } } bfs1(); suc = 1e9; front = 1; while(front <= back) { int u = Q[front++]; if(vis2[u] != -1) suc = min(suc, vis[u] + vis2[u]); vis[u] = -1; } if(suc == 1e9) suc = -1; printf("%d\n", suc); } }
来源：博客园
作者：Inko
链接：https://www.cnblogs.com/Inko/p/11441164.html