SMMR-226: Two Water Tanks

#include <bits/stdc++.h>
using namespace std;
const int INF=1e9;
using pi = pair<int,int>;
using pii = pair< int , pair<int,int> >;
int main(){
    int t;
    scanf("%d",&t);
    while(t--){
        int n,m,want;
        scanf("%d %d %d",&n,&m,&want);

        map< pi , bool > visited;

        priority_queue <pii,vector<pii>,greater<pii>> pq;

        pq.push({ 0 , {0,0} });
        bool fl=false;

        while(pq.size()>0){
            int v1,v2,d;
            d=pq.top().first;
            v1=pq.top().second.first;
            v2=pq.top().second.second;
            pq.pop();

            if(visited[{v1,v2}]) continue;
            visited[{v1,v2}] = true;

            if(v1==want||v2==want){
                printf("%d",d);
                fl=true;
                break;
            }

            if(v1==0)//fill_1
                pq.push({d+1,{n,v2} });

            if(v2==0)//fill_2
                pq.push({d+1,{v1,m} });

            if(v1!=0)//throw away_1
                pq.push({d+1,{0,v2} });

            if(v2!=0)//throw away_2
                pq.push({d+1,{v1,0} });

            if(v1!=n){
                v1=v1+v2;
                if(v1>n){
                    v2=v1-n;
                    v1=n;
                }
                else v2=0;
                pq.push({d+1,{v1,v2}});
            }
            if(v2!=m){
                v2=v1+v2;
                if(v2>m){
                    v1=v2-m;
                    v2=m;
                }
                else v1=0;
                pq.push({d+1,{v1,v2}});
            }

        }
        if(!fl) printf("-1");
        printf("\n");
    }

    return 0;
}