1 /*
2 网络流之最大流Dinic算法模版
3 */
4 #include <cstring>
5 #include <cstdio>
6 #include <queue>
7 using namespace std;
8 const int maxn = 205;
9 const int inf = 0x3f3f3f3f;
10 struct
11 {
12 int c,f;//c为边的容量，f为边的容量
13 }edge[maxn][maxn];
14 int dis[maxn];
15 int v,e;
16 bool bfs()//利用bfs进行分层处理，当汇点无法分层时得到最大流
17 {
18 memset(dis,0,sizeof dis);
19 queue<int> q;
20 q.push(1);
21 dis[1] = 1;
22 while(!q.empty())
23 {
24 int u = q.front(); q.pop();
25 for(int i = 1; i <= v; ++i)
26 if(!dis[i] && edge[u][i].c > edge[u][i].f)
27 {dis[i] = dis[u] + 1;q.push(i);}
28 }
29 return dis[v] != 0;
30 }
31 int dfs(int u,int c)//增广
32 {
33 if(u == v) return c;
34 int temp = c;
35 for(int i = 1; i <= v && temp; ++i)
36 {
37 if(dis[i] != dis[u] + 1 || edge[u][i].c <= edge[u][i].f) continue;
38 int t = dfs(i,min(temp,edge[u][i].c - edge[u][i].f));
39 edge[u][i].f += t; edge[i][u].f -= t; temp -= t;
40 }
41 return c - temp;
42 }
43 int dinic()
44 {
45 int ans = 0;
46 while(bfs())
47 while(int t = dfs(1,inf))
48 ans += t;
49 return ans;
50 }
51 int main()
52 {
53 while(~scanf("%d%d",&e,&v))
54 {
55 memset(edge,0,sizeof edge);
56 while(e--)
57 {
58 int x,y,z;
59 scanf("%d%d%d",&x,&y,&z);
60 edge[x][y].c += z;
61 }
62 int ans = dinic();
63 printf("%d\n",ans);
64 }
65 return 0;
66 }
