代码如下，自我感觉没问题，但是全WA

#include <iostream>
#include <cstring> 
using namespace std;

char a[102];
int letter[30];

bool f(int num){
	for (int i = 2 ; i*i <= num ; i++){
		if (num % i == 0){
			return false;
		}
	}
	return true;
}

void g(){
	for(int i = 0 ; i <= 30 ; i++) letter[i] = 0;
}

int main(){
	int tmpa = 0;
	int tmpi = 100;
	
	g();
	cin >> a;
	
	for(int i = 0 ; i < strlen(a); i++){
	    int tmp =  a[i] - 97;
	    letter[tmp]++;
	}
		
	for(int i = 0 ; i < strlen(a); i++){
		if(letter[i] > tmpa) tmpa = letter[i];
        if(letter[i] < tmpi) tmpi = letter[i];
	}
	
	if(f(tmpa - tmpi)){
		cout << "Lucky Word" <<endl;
		cout << tmpa - tmpi; 
	} 
	else{
		cout << "No Answer" <<endl;
		cout << "0";
	}
	return 0;	
}