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E.cpp
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E.cpp
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//#pragma GCC optimize "trapv"
#pragma GCC optimize("O3", "unroll-loops")
#pragma GCC target("avx2")
#include<bits/stdc++.h>
#define ll long long int
#define fab(a,b,i) for(int i=a;i<b;i++)
#define pb push_back
#define db double
#define mp make_pair
#define endl "\n"
#define f first
#define se second
#define all(x) x.begin(),x.end()
#define MOD 1000000007
#define vll vector<ll>
#define vi vector<int>
#define pii pair<int,int>
#define pll pair<ll,ll>
#define quick ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
ll add(ll x, ll y) {ll res = x + y; return (res >= MOD ? res - MOD : res);}
ll mul(ll x, ll y) {ll res = x * y; return (res >= MOD ? res % MOD : res);}
ll sub(ll x, ll y) {ll res = x - y; return (res < 0 ? res + MOD : res);}
ll power(ll x, ll y) {ll res = 1; x %= MOD; while (y) {if (y & 1)res = mul(res, x); y >>= 1; x = mul(x, x);} return res;}
ll mod_inv(ll x) {return power(x, MOD - 2);}
using namespace std;
const int N=2e5+5;
vector<int> v[N],dir[N];
vector<int> topo;
void dfs1(int src, bool vis[])
{
vis[src]=1;
for(auto i: dir[src])
{ if(!vis[i])
dfs1(i,vis);
}
topo.pb(src);
}
bool checkcycle(int src,bool vis[], bool recstack[])
{
bool ok=0;
vis[src]=1;
recstack[src]=1;
for(auto i:dir[src])
{
if(recstack[i])
return 1;
if (!vis[i])
ok|=checkcycle(i,vis,recstack);
}
recstack[src]=0;
return ok;
}
int main()
{ quick;
#ifndef ONLINE_JUDGE
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
int t;
cin>>t;
while(t--)
{
int n,m;
cin>>n>>m;
//cout<<n<<" "<<m<<endl;
fab(1,n+1,i)
dir[i].clear();
topo.clear();
vector< pair<int,int> > undir;
fab(0,m,i)
{
int ty,a,b;
cin>>ty>>a>>b;
if(ty==1)
{dir[a].pb(b);
//dir[b].pb(a);}
}
else
{
undir.pb({a,b});
}
}
bool vis[n+1],recstack[n+1];
memset(vis,0,sizeof(vis));
memset(recstack,0,sizeof(recstack));
bool ok=0;
fab(1,n+1,i)
{
if(!vis[i])
ok|=(checkcycle(i,vis,recstack));
}
if(ok)
{
cout<<"NO\n";
continue;
}
memset(vis,0,sizeof(vis));
fab(1,n+1,i)
{
if(!vis[i])
dfs1(i,vis);
}
reverse(all(topo));
map<int,int> pos;
fab(0,topo.size(),i)
{
pos[topo[i]]=i+1;
}
for(auto i: undir)
{
if(pos[i.f]<pos[i.se])
{
dir[i.f].pb(i.se);
}
else
{
dir[i.se].pb(i.f);
}
}
cout<<"YES\n";
fab(1,n+1,i)
{
for(auto j: dir[i])
cout<<i<<" "<<j<<endl;
}
fab(1,n+1,i)
dir[i].clear();
topo.clear();
}
cerr << "time taken : " << (float)clock() / CLOCKS_PER_SEC << " secs" << endl;
return 0;
}