python/TangDou/XiTi/1184.cpp

#include <bits/stdc++.h>

using namespace std;

//判断是不是质数
bool isPrime(int n) { //最快的方法
    if (n < 2) return false;
    if (n == 2 || n == 3) return true;
    if (n % 6 != 1 && n % 6 != 5) return false;
    for (int i = 5; i <= floor(sqrt(n)); i += 6)
        if (n % i == 0 || n % (i + 2) == 0)
            return false;
    return true;
}

int main() {
    string str;
    getline(cin, str);
    unordered_map<char, int> _map;
    //存入hash表
    for (int i = 0; i < str.length(); ++i) {
        _map[str[i]]++;
    }
    //迭代找到最大和最小
    unordered_map<char, int>::iterator it = _map.begin();
    int maxn = INT32_MIN, minn = INT32_MAX;
    while (it != _map.end()) {
        if (it->second > maxn) maxn = it->second;
        if (it->second < minn) minn = it->second;
        it++;
    }
    if (isPrime(maxn - minn)) {
        cout << "Lucky World" << endl;
        cout << maxn - minn << endl;
    } else {
        cout << "No Answer" << endl;
        cout << "0" << endl;
    }
    return 0;
}