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;
#define int long long   // <-----!!!!!!!!!!!!!!!!!!!

#define rep(i,n) for (int i=0;i<(n);i++)
#define rep2(i,a,b) for (int i=(a);i<(b);i++)
#define rrep(i,n) for (int i=(n)-1;i>=0;i--)
#define all(a) (a).begin(),(a).end()
#define rall(a) (a).rbegin(),(a).rend()
#define printV(v) for(auto&& x : v){cout << x << " ";} cout << endl
#define printVV(vv) for(auto&& v : vv){for(auto&& x : v){cout << x << " ";}cout << endl;}
#define printP(p) cout << p.first << " " << p.second << endl
#define printVP(vp) for(auto&& p : vp) printP(p);

typedef long long ll;
typedef pair<int, int> Pii;
typedef tuple<int, int, int> TUPLE;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<Pii> vp;
const int inf = 1e9;
const int mod = 1e9 + 7;
template<typename T> using Graph = vector<vector<T>>;

struct edge { int to, cap, cost, rev; };

int V;
const int MAX_V = 100;
vector<edge> G[MAX_V];
int dist[MAX_V];
int prevv[MAX_V], preve[MAX_V];

void add_edge(int from, int to, int cap, int cost) {
    G[from].emplace_back((edge){to, cap, cost, (int)G[to].size()});
    G[to].emplace_back((edge){from, 0, -cost, (int)G[from].size() - 1});
}

int min_cost_flow(int s, int t, int f) {
    int res = 0;
    while (f > 0) {
        fill(dist, dist + V, inf);
        dist[s] = 0;
        bool update = true;
        while (update) {
            update = false;
            for (int v = 0; v < V; v++) {
                if (dist[v] == inf) 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) {
                        dist[e.to] = dist[v] + e.cost;
                        prevv[e.to] = v;
                        preve[e.to] = i;
                        update = true;
                    }
                }
            }
        }

        if (dist[t] == inf) {
            return -1;
        }

        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 * dist[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;
}

signed main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);

    int E, F;
    cin >> V >> E >> F;
    rep(i, E) {
        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;
}