#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
using namespace std;
const int maxn = 410;
const int INF = 0x3f3f3f3f;
int a[maxn], down[maxn*maxn];
struct Edge {
    int from, to, flow, cap;
    Edge(int a, int b, int c, int d) : from(a), to(b), flow(c), cap(d) {}
};
struct Dinic {
    bool vis[maxn];
    int n, m, s, t, d[maxn], cur[maxn];
    vector<Edge> edges;
    vector<int> G[maxn];
    void init(int nn) {
        n = nn;
        edges.clear();
        for (int i = 0; i <= n + 5; i++) G[i].clear();
    }
    void addedge(int from, int to, int flow, int cap) {
        edges.push_back(Edge(from, to, flow, cap));
        edges.push_back(Edge(to, from, -flow, 0));
        m = edges.size();
        G[from].push_back(m-2);
        G[to].push_back(m-1);
    }
    bool bfs() {
        memset(vis, 0, sizeof(vis));
        queue<int> Q; Q.push(s);
        d[s] = 0;
        vis[s] = 1;
        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 > e.flow) {
                    vis[e.to] = 1;
                    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 - e.flow))) > 0) {
                e.flow += f;
                edges[G[x][i]^1].flow -= f;
                flow += f;
                a -= f;
                if (a == 0) break;
            }
        }
        return flow;
    }
    int maxflow(int ss, int tt) {
        s = ss, t = tt;
        int flow = 0;
        while (bfs()) {
            memset(cur, 0, sizeof(cur));
            flow += dfs(s, INF);
        }
        return flow;
    }
    void output(int m) {
        for (int i = 1; i <= m; i++) {
            printf("%d\n", down[i] + edges[(i-1)*2].flow);
        }
    }
}dinic;
int main() {
    int T, n, m, from, to, up;
    scanf("%d", &T);
    for (int kase = 1; kase <= T; kase++) {
        scanf("%d %d", &n, &m);
        dinic.init(n);
        memset(a, 0, sizeof(a));
        for (int i = 1; i <= m; i++) {
            scanf("%d %d %d %d", &from, &to, &down[i], &up);
            dinic.addedge(from, to, 0, up - down[i]);
            a[from] -= down[i];
            a[to] += down[i];
        }
        int ss = n + 1, tt = n + 2, sum = 0;
        for (int i = 1; i <= n; i++) {
            if (a[i] > 0) {
                dinic.addedge(ss, i, 0, a[i]);
            }
            else {
                sum -= a[i];
                dinic.addedge(i, tt, 0, -a[i]);
            }
        }
        if (kase != 1) printf("\n");
        int temp = dinic.maxflow(ss, tt);
        if (temp != sum) {
            printf("NO\n");
        }
        else {
            printf("YES\n");
            dinic.output(m);
        }
    }
    return 0;
}