pku1325 Machine Schedule

涉及到二分图（二部图）、最小覆盖、最大匹配、匈牙利算法（匈牙利树）、增广路

 

原来这就是传说中的匈牙利

代码上很简单，但思想非常精妙

 

//pku1325 Machine Schedule#include <cstdio>#include <cstring>#define MAX_N 100char map[MAX_N][MAX_N];char mark[MAX_N];long link[MAX_N];long N, M;bool path(long x){long y;for (y=1; y<M; y++){if (0==mark[y] && map[x][y]){mark[y] = 1;if (0==link[y] || path(link[y])){link[y] = x;return true;}}}return false;}int main(){long n, K;while (3 == scanf("%ld%ld%ld", &N, &M, &K)){for (n=1; n<N; n++)memset(map[n], 0, M*sizeof(map[0][0]));memset(link, 0, M*sizeof(link[0]));long i, x, y, k;for (k=0; k<K; k++){scanf("%ld%ld%ld", &i, &x, &y);if (0!=x && 0!=y){map[x][y] = 1;}}long total = 0;for (n=1; n<N; n++){memset(mark, 0, M*sizeof(mark[0]));if (path(n))total++;}printf("%ld/n", total);}return 0;}