[最短路]Open the Lock

#include <iostream>
#include<cstdio>
#include<cstring>
#include<queue>
#include<algorithm>
using namespace std;

int st,ed;
int vis[10005];
int tmp[5];
struct Node{
  int val,step;
  bool operator <(const Node b)const{
    return step>b.step;
  }
};
priority_queue<Node> q;

int bfs(){
  while(!q.empty()) q.pop();
  vis[st]=1;q.push(Node{st,0});
  while(!q.empty()){
    Node top=q.top();q.pop();
    int val=top.val,step=top.step;
    if(val==ed) return step;
    tmp[1]=(val/1000)%10,tmp[2]=(val/100)%10;
    tmp[3]=(val/10)%10,tmp[4]=(val/1)%10;
    int cpy;
    for(int i=1;i<=4;i++){
        cpy=tmp[i];
        if(tmp[i]==9) tmp[i]=1;
        else tmp[i]++;
        int now=tmp[1]*1000+tmp[2]*100+tmp[3]*10+tmp[4];
        if(!vis[now]) vis[now]=1,q.push(Node{now,step+1});
        tmp[i]=cpy;
    }
    for(int i=1;i<=4;i++){
        cpy=tmp[i];
        if(tmp[i]==1) tmp[i]=9;
        else tmp[i]--;
        int now=tmp[1]*1000+tmp[2]*100+tmp[3]*10+tmp[4];
        if(!vis[now]) vis[now]=1,q.push(Node{now,step+1});
        tmp[i]=cpy;
    }
    for(int i=1;i<=3;i++){
        swap(tmp[i],tmp[i+1]);
        int now=tmp[1]*1000+tmp[2]*100+tmp[3]*10+tmp[4];
        if(!vis[now]) vis[now]=1,q.push(Node{now,step+1});
        swap(tmp[i],tmp[i+1]);
    }
  }
  return -1;
}

int main()
{
    int t;scanf("%d",&t);
    while(t--){
        memset(vis,0,sizeof(vis));
        scanf("%d%d",&st,&ed);
        int ans=bfs();
        printf("%d\n",ans);
    }
    return 0;
}