题目来源:http://acm.hdu.edu.cn/showproblem.php?pid=3549
代码:
#include <bits/stdc++.h>
#define ll long long
using namespace std;
struct edge{
int to,next,cap,rev;
}e[10010];
bool vis[1010];
int head[310],n,m,cnt=0;
void ins(int s,int t,int c) {
e[++cnt].to = t;
e[cnt].next = head[s];
head[s] = cnt;
e[cnt].cap = c;
e[cnt].rev = cnt + 1;
e[++cnt].to = s;
e[cnt].next = head[t];
head[t] = cnt;
e[cnt].cap = 0;
e[cnt].rev = cnt - 1;
}
int dfs(int v,int t,int f) {
if (v == t)return f;
vis[v] = 1;
for (int i = head[v]; i; i = e[i].next) {
if (!vis[e[i].to] && e[i].cap > 0) {
int d = dfs(e[i].to, t, min(f, e[i].cap));
if (d > 0) {
e[i].cap -= d;
e[e[i].rev].cap += d;
return d;
}
}
}
return 0;
}
int max_flow(int s,int t) {
int flow = 0;
for (;;) {
memset(vis, 0, sizeof(vis));
int f = dfs(s, t, 1e9);
if (f == 0)return flow;
flow += f;
}
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int _;
cin >> _;
for (int sce = 1; sce <= _; ++sce) {
memset(head, 0, sizeof(head));
memset(e, 0, sizeof(e));
cnt = 0;
cin >> n >> m;
for (int i = 1; i <= m; ++i) {
int x, y, z;
cin >> x >> y >> z;
ins(x, y, z);
}
cout << "Case " << sce << ": " << max_flow(1, n) << endl;
}
return 0;
}