Problem: Examples

Input

4 5 2
0 1 2 1
0 2 1 2
1 2 1 1
1 3 1 3
2 3 2 1


Output

6


Input




Output

Solution (in CPP):

Solution:
#include "bits/stdc++.h"
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int, int> PI;
typedef pair<LL, LL> PLL;
const LL MOD = 1000000007LL;
const int inf = 1e9;
const LL INF = 1e18;
const int MAX_V = 100;
struct edge {
	int to, cap, cost, rev;
	edge(int to, int cap, int cost, int rev) :to(to), cap(cap), cost(cost), rev(rev) {}
};
vector<edge> G[MAX_V];
int h[MAX_V];
int dist[MAX_V];
int prevv[MAX_V], preve[MAX_V];
int V;
void add_edge(int from, int to, int cap, int cost) {
	G[from].emplace_back(to, cap, cost, G[to].size());
	G[to].emplace_back(from, 0, -cost, G[from].size() - 1);
}
int min_cost_flow(int s, int t, int f) {
	int res = 0;
	fill(h, h + V, 0);
	while (f > 0) {
		priority_queue<PI, vector<PI>, greater<PI>> que;
		fill(dist, dist + V, inf);
		dist[s] = 0;
		que.push(PI(0, s));
		while (!que.empty()) {
			PI p = que.top(); que.pop();
			int v = p.second;
			if (dist[v] < p.first) continue;
			for (int i = 0; i < G[v].size(); i++) {
				edge e = G[v][i];
				if (e.cap > 0 && dist[e.to] > dist[v] + e.cost + h[v] - h[e.to]) {
					dist[e.to] = dist[v] + e.cost + h[v] - h[e.to];
					prevv[e.to] = v;
					preve[e.to] = i;
					que.push(PI(dist[e.to], e.to));
				}
			}
		}
		if (dist[t] == inf) return -1;
		for (int v = 0; v < V; v++) h[v] += dist[v];
		int d = f;
		for (int v = t; v != s; v = prevv[v]) {
			d = min(d, G[prevv[v]][preve[v]].cap);
		}
		f -= d;
		res += d*h[t];
		for (int v = t; v != s; v = prevv[v]) {
			edge &e = G[prevv[v]][preve[v]];
			e.cap -= d;
			G[v][e.rev].cap += d;
		}
	}
	return res;
}
int main() {
	cin >> V;
	int E, F;
	cin >> E >> F;
	for (int i = 0; i < E; i++) {
		int u, v, c, d;
		cin >> u >> v >> c >> d;
		add_edge(u, v, c, d);
	}
	cout << min_cost_flow(0, V - 1, F) << endl;
}