題目連結

#include <bits/stdc++.h>
using namespace std;
long long sushu(long long x,long long y){
    int i,i1,i2,i3,i4,flag=0;
    long long c,palindrom;
    if((x==5)&&(y>=11)) cout<<"5"<<endl<<"7"<<endl<<"11"<<endl;
    if((x==7)&&(y>=11
 
)) cout<<"7"<<endl<<"11"<<endl;
    for(i=10;i<=10000;i++){
        i1=i/1000;
        i2=(i/100)%10;
        i3=(i/10)%10;
        i4=i%10;
        if(i<100) palindrom=i3*100+i4*10+i3;
        else if(i<1000) palindrom=i2*10000+i3*1000+i4*100+i3*10+i2;
        else palindrom=i1*1000000+i2*100000+i3*10000+i4*1000+i3*100+i2*10
 
+i1;
        if((x<=palindrom)&&(y>=palindrom)){
            flag=0;
            for(c=2;c<=sqrt(palindrom);c++){
                if(palindrom%c==0){
                    flag=1;
                    break;
                }
            }
            if(flag==0) cout<<palindrom<<endl;
        }
    }
}
int
 
 main(){
    long long a,b;
    cin>>a>>b;
    sushu(a,b);
    return 0;
}