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| #include <iostream>
#include <algorithm>
#include <string>
#include <cstring>
#include <queue>
using namespace std;
const int maxn = 10005;
const int inf = 0x3f3f3f3f;
typedef long long ll;
int head[maxn];
struct edge
{
int v,w,next;
} edge[10005];
bool vis[10005];
int tot;
int deep[maxn];
int bfs(int s, int t)
{
queue<int>Q;
memset(deep, 0, sizeof(deep));
deep[s] = 1;
Q.push(s);
while(!Q.empty())
{
int u = Q.front();
Q.pop();
for(int k = head[u]; k != -1; k = edge[k].next)
{
int v = edge[k].v;
int w = edge[k].w;
if(deep[v] == 0 && w > 0)
{
deep[v] = deep[u] + 1;
Q.push(v);
}
}
}
if(deep[t] == 0)
return 0;
return 1;
}
void add(int u,int v, int w)
{
edge[tot].v = v;
edge[tot].w = w;
edge[tot].next = head[u];
head[u] = tot;
tot++;
}
int t;
int dfs(int s, int dis)
{
if(s == t)
return dis;
for(int k = head[s]; k != -1; k = edge[k].next)
{
int v = edge[k].v;
int w = edge[k].w;
if(deep[v] == deep[s] + 1 && w > 0)
{
int d = dfs(v,min(w, dis));
if(d > 0)
{
edge[k].w -= d;
edge[k^1].w += d;
return d;
}
}
}
return 0;
}
int main()
{
int n, m,u,v,w;
while(cin >> m >> n)
{
tot = 0;
t = n;
memset(head, -1, sizeof(head));
for(int i = 1; i <= m; ++i)
{
scanf("%d %d %d",&u,&v,&w);
add(u,v,w);
add(v,u,0);
}
ll sum = 0;
while(bfs(1,n))
{
while(int d = dfs(1, inf))
sum += d;
}
cout << sum << '\n';
}
}
|