算法
二分图+最小点覆盖
思路
详见《进阶指南》
代码
#include <cstdio> #include <vector> #include <cstring> #include <iostream> using namespace std; const int N = 56; int n, m, tot = 1, a[N][N][2], f[N*N], ans; char s[N][N]; bool v[N*N]; vector<int> e[N*N]; bool dfs(int x) { for (unsigned int i = 0; i < e[x].size(); i++) { int y = e[x][i]; if (v[y]) continue; v[y] = 1; if (!f[y] || dfs(f[y])) { f[y] = x; return 1; } } return 0; } int main() { cin >> n >> m; for (int i = 1; i <= n; i++) scanf("%s", s[i] + 1); for (int i = 1; i <= n; i++) for (int j = 1; j <= m + 1; j++) if (s[i][j] == ‘*‘) a[i][j][0] = tot; else ++tot; int t = tot; for (int j = 1; j <= m; j++) for (int i = 1; i <= n + 1; i++) if (s[i][j] == ‘*‘) a[i][j][1] = tot; else ++tot; for (int i = 1; i <= n; i++) for (int j = 1; j <= m; j++) if (s[i][j] == ‘*‘) { e[a[i][j][0]].push_back(a[i][j][1]); e[a[i][j][1]].push_back(a[i][j][0]); } for (int i = 1; i < t; i++) { memset(v, 0, sizeof(v)); ans += dfs(i); } cout << ans << endl; return 0; } 作者:ruanmowen 链接:https://www.acwing.com/activity/content/code/content/278239/ 来源:AcWing 著作权归作者所有。商业转载请联系作者获得授权,非商业转载请注明出处。