捻りはありません

codeiq_slime-hopper.cc

#include<bits/stdc++.h>

using namespace std;
typedef long long int ll;

int m,n;
int ip,iq;
bool nonprime[100001];

void makeprime(int high){
    int i,j;
    nonprime[0]=true;
    nonprime[1]=true;
    for (i=2;i<=high;i++){
        if (!nonprime[i]){
            for (j=i*2;j<=high;j+=i){
                nonprime[j]=true;
            }
        }
    }
}

int main(){
    int i,j,k,l;
    
    cin>>ip>>iq;

    makeprime(iq);
    
    queue<pair<int,int>> q;
    q.push(make_pair(ip,0));
    
    int t,e,cnt,digit;
    while (!q.empty()){
        e  =q.front().first;
        cnt=q.front().second;
        q.pop();
        
        if (e==iq){
        l_final:
            cout<<cnt<<endl;
            return 0;
        }
        
        int digit=1;
        while (digit<e)digit*=10;
        
        // rightpush
        for (i=1;i<10;i++){
            t=e*10+i;
            if (t==iq) {cnt++;goto l_final;}
            if (t<=iq && !nonprime[t]){
                q.push(make_pair(t,cnt+1));
                nonprime[t]=true;
            }
        }
        
        if (e>=10){
            // rightpop
            t=e/10;
            if (t==iq) {cnt++;goto l_final;}
            if (t<=iq && !nonprime[t]){
                q.push(make_pair(t,cnt+1));
                nonprime[t]=true;
            }
            
            t=e%(digit/10);
            if (t/(digit/100)){
                // leftpop
                if (t==iq) {cnt++;goto l_final;}
                if (t<=iq && !nonprime[t]){
                    q.push(make_pair(t,cnt+1));
                    nonprime[t]=true;
                }
            }
        }
        //leftpush
        for (i=1;i<10;i++){
            t=e+i*digit;
            if (t==iq) {cnt++;goto l_final;}
            if (t<=iq && !nonprime[t]){
                q.push(make_pair(t,cnt+1));
                nonprime[t]=true;
            }
        }
    }
    
    cout<<-1<<endl;

    return 0;
}