Title Description

If that, given a network diagram, and the source and sink, each side units is known maximum flow and traffic charges, which determine the maximum flow and minimum cost network in the case of maximum flow.

Input Format

The first row contains four positive integers N, M, S, T, respectively, the number of points, there are the number of edges, number source, sink point number.

Next M lines contains four integer ui, vi, wi, fi, denotes the i th ui from there to the edge and arriving at VI, the right side of wi (i.e., the side of the maximum flow rate Wi), per unit flow rate fee fi.

Output Format

One line containing two integers, followed by the maximum flow and minimum cost at maximum flow conditions.

Sample input and output

Input # 1copy

4 5 4 3
4 2 30 2
4 3 20 3
2 3 20 1
2 1 30 9
1 3 40 5

Output # 1copy

50 280

#include<bits/stdc++.h>
const int maxn = 5e4 + 10;
int head[maxn];
int vis[maxn];
int dis[maxn];
int flow[maxn];
int pre[maxn];
int last[maxn];
int tot;
int n, m, s, t;
using namespace std;
struct node{
	int to;
	int next;
	int f;
	int w;
	node() {}
	node(int a, int b, int c, int d) : to(a), next(b), f(c), w(d) {}
}edge[maxn * 10];

void edgeadd(int a, int b, int c, int d){
	edge[tot] = node(b, head[a], c, d);
	head[a] = tot++;
	edge[tot] = node(a, head[b], 0, -d);
	head[b] = tot++;
}

void init(){
	memset(head, -1, sizeof(head));
	tot = 0;
}

void spfainit(){
	memset(vis, 0, sizeof(vis));
	memset(dis, 0X3f3f, sizeof(dis));
	memset(flow, 0x3f3f, sizeof(flow));
}

bool spfa(){
	spfainit();
	queue<int> q;
	q.push(s);
	pre[t] = -1;
	vis[s] = 1;
	dis[s] = 0;
	//flow[s] = 0;
	while(!q.empty()){
		int nw = q.front();
		q.pop();
		vis[nw] = 0;
		for(int i = head[nw]; i != -1; i = edge[i].next){
			int y = edge[i].to;
			int w = edge[i].w;
			int f = edge[i].f;
			if(f && dis[y] > dis[nw] + w){
				dis[y] = dis[nw] + w;
				flow[y] = min(flow[nw], f);
				pre[y] = nw;
				last[y] = i;
				if(!vis[y]){
					q.push(y);
					vis[y] = 1;
				}
			}
		}
	}
	return pre[t] != -1;
}

void dinic(){
	int maxflow = 0, minw = 0;
	while(spfa()){
	maxflow += flow[t];
	minw += flow[t] * dis[t];
		int x = t;
		while(x != s){
			edge[last[x]].f -= flow[t];
			edge[(last[x] ^ 1)].f += flow[t];
			x = pre[x];
		}
	}
	cout << maxflow << " " << minw << endl;
}
int main(){
	ios::sync_with_stdio(false);
	cin >> n >> m >> s >> t;
	init();
	for(int i = 1; i <= m; i++){
		int a, b, c, d;
		cin >> a >> b >> c >> d;
		edgeadd(a, b, c, d);
	}
	dinic();
	return 0;
}