题解

十分简单，只要会判断素数就行了

上代码

#include<bits/stdc++.h>
using namespace std;
bool is_s(int p){
    if(p<2){
        return 0;
    }
    bool flag  = 1;
    for(int i  = 2;i<p;i++){
        if(p%i==0){
            flag = 0;
            break;
        }
    }
    return flag;
}
int a[100]={};
int main(){
    string s;
    cin>>s;

    for(int i = 0;i<s.size();i++)a[s[i]]++;
    int maxn=INT_MIN,minn=INT_MAX;

    for(int i = 'a';i<='z';i++){
        if(a[i]>maxn)maxn=a[i];
        if(a[i]<minn&&a[i]!=0)minn=a[i];
    }
    int p = maxn-minn;
    bool flag = is_s(p);
    if(flag)cout<<"Lucky Word\n"<<p;
    else cout<<"No Answer\n0";
    return 0;
}