SMMR-226: Two Water Tanks

#include<bits/stdc++.h>
using namespace std;
typedef long long int lld;
typedef pair<lld,pair<lld,lld>> pipii;

int water(lld n,lld m,lld d){

    map<int,map<int,bool>> visited;
    priority_queue<pipii,vector<pipii>,greater<pipii>> q;
    q.push({0,{0,0}});

    while(!q.empty()){
        lld u=q.top().second.first,v=q.top().second.second,k=q.top().first;
        q.pop();

        if(u==d||v==d){return k;}

        if(visited[u][v]){continue;}
        visited[u][v]=true;

        //เติมน้ำ
        if(u<n){q.push({k+1,{n,v}});}
        if(v<m){q.push({k+1,{u,m}});}
        //เทน้ำออก
        if(u>0){q.push({k+1,{0,v}});}
        if(v>0){q.push({k+1,{u,0}});}
        //ย้ายน้ำ  u->v
        if(u>0&&v<m){
            lld a= u-(m-v); if(a<0){a=0;}
            lld b= u+v; if(b>m){b=m;}
            q.push({k+1,{a,b}});
        }
        //ย้ายน้ำ  v->u
        if(u<n&&v>0){
            lld a=u+v; if(a>n){a=n;}
            lld b=v-(n-u); if(b<0){b=0;}
            q.push({k+1,{a,b}});
        }
    }
    return -1;
}



int main(){
    int t; scanf("%d",&t);
    for(int p=0;p<t;p++){
    lld n,m,d;
    scanf("%lld %lld %lld",&n,&m,&d);
    lld ans=water(n,m,d);
    printf("%lld\n",ans);

    }
    return 0;
}