Absolute Differences

#include <bits/stdc++.h>
using namespace std;

#define ll     long long
#define _test   int _TEST; cin>>_TEST; while(_TEST--)
#define pb     push_back

int main()
{
    _test
    {
        int n, m, k;
        cin>>n>>m>>k;

        vector<ll int> mmin(n, -1e18);
        vector<ll int> mmax(n,  1e18);

        int f = 1;

        vector<vector<array<ll int, 2>>> va(n);
        vector<int> st;

        for(int i=0; i<m; i++)
        {
            ll int pos, val;
            cin>>pos>>val;

            pos--;

            if(mmin[pos]>val || mmax[pos]<val)
                f = 0;

            st.pb(pos);

            mmin[pos] = mmax[pos] = val;
        }

        for(int i=0; i<k; i++)
        {
            ll int u, v, d;
            cin>>u>>v>>d, u--, v--;

            va[u].pb({v, d});
            va[v].pb({u, d});
        }

        vector<int> vis(n);
        queue<int> que;

        for(int _=0; _<n && f; _++)
        {
            fill(vis.begin(), vis.end(), 0);

            for(auto e: st)     que.push(e), vis[e] = 1;

            while(que.size() && f)
            {
                auto e = que.front();
                que.pop();

                for(auto [v, d]: va[e])
                {
                    mmin[v] = max(mmin[v], mmin[e]-d);
                    mmax[v] = min(mmax[v], mmax[e]+d);

                    f &= (mmin[v] <= mmax[v]);

                    if(!vis[v])
                    {
                        vis[v] = 1;
                        que.push(v);
                    }
                }
            }
        }

        if(f)       cout<<"YES\n";
        else        cout<<"NO\n";
    }
}