POJ 3308 Paratroopers 最小点权覆盖 求最小割

#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <climits>
#include <string>
#include <iostream>
#include <map>
#include <cstdlib>
#include <list>
#include <set>
#include <queue>
#include <stack>

using namespace std;

typedef long long LL;
const int maxn = 105;
const double INF = 1e60;
const double eps = 1e-9;
int level[maxn],n,m,c,q[maxn],qs,qe;
double cap[maxn][maxn];
int s,t;

bool bfs() {
qs = qe = 0;
memset(level,0,sizeof(level));
level[s] = 1;
q[qe++] = s;
while(qs < qe) {
int now = q[qs++];
if(now == t) break;
for(int i = s;i <= t;i++) if(cap[now][i] >= eps) {
if(level[i] == 0) {
q[qe++] = i; level[i] = level[now] + 1;
}
}
}
return level[t];
}

double dfs(int now,double alpha) {
if(now == t) return alpha;
double sum = 0;
for(int i = s;i <= t && alpha >= eps;i++) {
if(cap[now][i] >= eps && level[i] == level[now] + 1) {
double ret = dfs(i,min(alpha,cap[now][i]));
sum += ret; alpha -= ret;
cap[now][i] -= ret; cap[i][now] += ret;
}
}
if(sum < eps) level[now] = -1;
return sum;
}

void solve() {
double ans = 0;
while(bfs()) ans += dfs(s,INF);
printf("%.4f\n",exp(ans));
}

int main() {
int T; scanf("%d",&T);
while(T--) {
memset(cap,0,sizeof(cap));
scanf("%d%d%d",&n,&m,&c);
s = 0; t = n + m + 1;
for(int i = 1;i <= n;i++) {
double tmp; scanf("%lf",&tmp);
cap[s][i] = log(tmp);
}
for(int i = 1;i <= m;i++) {
double tmp; scanf("%lf",&tmp);
cap[i + n][t] = log(tmp);
}
for(int i = 1;i <= c;i++) {
int a,b; scanf("%d%d",&a,&b);
cap[a][b + n] = INF;
}
solve();
}
return 0;
}