[ACdream 1211 Reactor Cooling]无源无汇有上下界的可行流

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#pragma comment(linker, "/STACK:10240000")
#include <map>
#include <set>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <vector>
#include <cstdio>
#include <string>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

#define X                   first
#define Y                   second
#define pb                  push_back
#define mp                  make_pair
#define all(a)              (a).begin(), (a).end()
#define fillchar(a, x)      memset(a, x, sizeof(a))
#define fillarray(a, b)     memcpy(a, b, sizeof(a))

typedef long long ll;
typedef pair<int, int> pii;
typedef unsigned long long ull;

#ifndef ONLINE_JUDGE
namespace Debug {
void RI(vector<int>&a,int n){a.resize(n);for(int i=0;i<n;i++)scanf("%d",&a[i]);}
void RI(){}void RI(int&X){scanf("%d",&X);}template<typename...R>
void RI(int&f,R&...r){RI(f);RI(r...);}void RI(int*p,int*q){int d=p<q?1:-1;
while(p!=q){scanf("%d",p);p+=d;}}void print(){cout<<endl;}template<typename T>
void print(const T t){cout<<t<<endl;}template<typename F,typename...R>
void print(const F f,const R...r){cout<<f<<", ";print(r...);}template<typename T>
void print(T*p, T*q){int d=p<q?1:-1;while(p!=q){cout<<*p<<", ";p+=d;}cout<<endl;}
}
#endif // ONLINE_JUDGE

template<typename T>bool umax(T&a, const T&b){return b<=a?false:(a=b,true);}
template<typename T>bool umin(T&a, const T&b){return b>=a?false:(a=b,true);}

const double PI = acos(-1.0);
const int INF = 0x3f3f3f3f;
const double EPS = 1e-14;

/* -------------------------------------------------------------------------------- */

const int maxn = 2e2 + 7;

struct Dinic {
private:
    //const static int maxn = 1e3 + 7;
    struct Edge {
        int from, to, cap, least;
        Edge(int u, int v, int w, int l): from(u), to(v), cap(w), least(l) {}
    };
    int s, t;
    vector<Edge> edges;
    vector<int> G[maxn];
    bool vis[maxn];
    int d[maxn], cur[maxn];

    bool bfs() {
        memset(vis, 0, sizeof(vis));
        queue<int> Q;
        Q.push(s);
        d[s] = 0;
        vis[s] = true;
        while (!Q.empty()) {
            int x = Q.front(); Q.pop();
            for (int i = 0; i < G[x].size(); i ++) {
                Edge &e = edges[G[x][i]];
                if (!vis[e.to] && e.cap) {
                    vis[e.to] = true;
                    d[e.to] = d[x] + 1;
                    Q.push(e.to);
                }
            }
        }
        return vis[t];
    }
    int dfs(int x, int a) {
        if (x == t || a == 0) return a;
        int flow = 0, f;
        for (int &i = cur[x]; i < G[x].size(); i ++) {
            Edge &e = edges[G[x][i]];
            if (d[x] + 1 == d[e.to] && (f = dfs(e.to, min(a, e.cap))) > 0) {
                e.cap -= f;
                edges[G[x][i] ^ 1].cap += f;
                flow += f;
                a -= f;
                if (a == 0) break;
            }
        }
        return flow;
    }

public:
    void clear() {
        for (int i = 0; i < maxn; i ++) G[i].clear();
        edges.clear();
        memset(d, 0, sizeof(d));
    }
    void add(int from, int to, int cap, int least) {
        edges.push_back(Edge(from, to, cap, least));
        edges.push_back(Edge(to, from, 0, least));
        int m = edges.size();
        G[from].push_back(m - 2);
        G[to].push_back(m - 1);
    }

    int solve(int s, int t) {
        this->s = s; this->t = t;
        int flow = 0;
        while (bfs()) {
            memset(cur, 0, sizeof(cur));
            flow += dfs(s, 1e9);
        }
        return flow;
    }

    void out(int m) {
        for (int i = 0; i < m; i ++) {
            printf("%d\n", edges[i << 1].least + edges[i << 1 | 1].cap);
        }
    }
};
Dinic solver;
int tob[maxn], fromb[maxn];

int main() {
#ifndef ONLINE_JUDGE
    freopen("in.txt", "r", stdin);
    //freopen("out.txt", "w", stdout);
#endif // ONLINE_JUDGE
    int n, m;
    while (cin >> n >> m) {
        solver.clear();
        fillchar(tob, 0);
        fillchar(fromb, 0);
        for (int i = 0; i < m; i ++) {
            int u, v, b, c;
            scanf("%d%d%d%d", &u, &v, &b, &c);
            solver.add(u, v, c - b, b);
            tob[v] += b;
            fromb[u] += b;
        }
        int total = 0;
        for (int i = 1; i <= n; i ++) {
            int dif = tob[i] - fromb[i];
            if (dif > 0) solver.add(0, i, dif, 0);
            if (dif < 0) solver.add(i, n + 1, - dif, 0);
            total += abs(dif);
        }
        if (solver.solve(0, n + 1) != total / 2) puts("NO");
        else {
            puts("YES");
            solver.out(m);
        }
    }
    return 0;
}