#include<bits/stdc++.h>

using namespace std;

const int N=;

int ne[N],num,n,m,d[N],S,T,a,b,c,low[N],fi[N],zz[N],sl[N],dis[N],q[N];

void jb(int x,int y,int z)

{

    ne[num]=fi[x];

    fi[x]=num;

    zz[num]=y;

    sl[num++]=z;

    swap(x,y);

    z=;

    ne[num]=fi[x];

    fi[x]=num;

    zz[num]=y;

    sl[num++]=z;

}

int bfs()

{

    memset(dis,0xff,sizeof dis);

    dis[]=;

    int l=,r=;

    q[]=;

    while (l<r)

     {

         int j=q[++l];

         for (int i=fi[j];i!=-;i=ne[i])

          if (dis[zz[i]]<&&sl[i]>)

           {

               dis[zz[i]]=dis[j]+;

               q[++r]=zz[i];

           }

     }

    if (dis[n]>)return ;

    return ;

}

int find(int x,int low)

{

    int b=;

    if (x==n)return low;

    for (int i=fi[x];i!=-;i=ne[i])

     if (sl[i]>&&dis[zz[i]]==dis[x]+&&(b=find(zz[i],min(low,sl[i]))))

      {

          sl[i]-=b;

          sl[i^]+=b;

          return b;

      }

    return ;

}

int main()

{

    scanf("%d",&T);

    while (T--)

     {

         memset(fi,-,sizeof fi);

         num=;

         memset(d,,sizeof d);

         scanf("%d%d",&n,&m);

         for (int i=;i<m;i++)

          {

              scanf("%d%d%d%d",&a,&b,&low[i],&c);

              jb(a+,b+,c-low[i]);

              d[a]+=low[i];d[b]-=low[i];

          }

         int tot=;

        for (int i=;i<=n;i++)

         {

             if (d[i]<)jb(,i+,-d[i]);

             else jb(i+,n+,d[i]),tot+=d[i];

         }

        n+=;

        int t,ans=;

        while (bfs())

         while (t=find(,1e9))ans+=t;

        if (tot!=ans)puts("NO");

        else

         {

             puts("YES");

             for (int i=;i<m;i++)

              printf("%d\n",sl[(i<<)^]+low[i]);

         }

        puts("");

     }

}