网络流Ford-Fulkerson模板代码：
#include<iostream>
#include<vector>
#include<cstring>
#include<cstdio>
using namespace std;
const int N = 250;
const int INF = 0x3f3f3f3f;
struct Node
{int to;int cap;int rev;
};
vector<Node> v[N];
bool used[N];
void add_Node(int from, int to, int cap)
{v[from].push_back((Node){to, cap, v[to].size()});v[to].push_back((Node){from, 0, v[from].size() - 1}); //相当于前向星
}
int dfs(int s, int t, int f)
{if(s == t)return f;used[s] = true;for(int i = 0; i < v[s].size(); i++){Node &tmp = v[s][i];if(used[tmp.to] == false && tmp.cap > 0){int d = dfs(tmp.to, t, min(f, tmp.cap));if(d > 0){tmp.cap -= d;v[tmp.to][tmp.rev].cap += d;return d;}}}return 0;
}
int max_flow(int s, int t)
{int flow = 0;for(;;){memset(used, false, sizeof(used));int f = dfs(s, t, INF);if(f == 0)return flow;flow += f;}
}
int main()
{int n, m;while(~scanf("%d%d", &n, &m)){memset(v, 0, sizeof(v));for(int i = 0; i < n; i++){int x, y, z;scanf("%d%d%d", &x, &y, &z);add_Node(x, y, z);}printf("%d\n", max_flow(1, m));}return 0;
}
Dinic模板：
#include<iostream>
#include<cstring>
#include<cstdio>
using namespace std;
int n, m, maxflow;//n点数, m边数
int edge[250][250];//邻接矩阵
int dis[250];//距源点的距离，分层图
int q[250];//BFS队列
int BFS()
{int u, v;memset(dis, -1, sizeof(dis));dis[1] = 0;int head = 0, tail = 1;q[1] = 1;while(head < tail){u = q[++head];for(int v = 1; v <= n; v++)if(dis[v] < 0 && edge[u][v] > 0){dis[v] = dis[u] + 1;q[++tail] = v;}}if(dis[n] > 0)return 1;elsereturn 0;//汇点的DIS小于零,表明BFS不到汇点
}
//dinic代表一次增广,函数返回本次增广的流量,返回0表示无法增广
int dinic(int u, int low)Low是源点到现在最窄的(剩余流量最小)的边的剩余流量
{int flow;if(u == n)//是汇点return low;for(int v = 1; v <= n; v++)if(edge[u][v] > 0 && dis[v] == dis[u] + 1 && (flow = dinic(v, min(low, edge[u][v]))))//联通且是分层图的下一层且能到汇点(flow <> 0){edge[u][v] -= flow;edge[v][u] += flow;return flow;}return 0;
}
int main()
{int u, v, w, flow;while(scanf("%d%d", &m, &n) != EOF){memset(edge, 0, sizeof(edge));for(int i = 1; i <= m; i++){scanf("%d%d%d", &u, &v, &w);edge[u][v] += w;}maxflow = 0;while(BFS())//要不停地建立分层图,如果BFS不到汇点才结束{while(flow = dinic(1, 0x3f3f3f3f))//一次BFS要不停地找增广路,直到找不到为止maxflow += flow;}printf("%d\n", maxflow);}return 0;
}