3.13 判读是否是对称素数

输入：11 101 272

输出：

Yes

Yes

No

#include<fstream>
#include<iostream>
#include<sstream>
#include<string>
#include<cmath>
using namespace std;

bool isPrime(int);
bool isSymmetry(int);

int main(){
ifstream cin("data.txt");
int num;
while(cin >> num){
if(isPrime(num) && isSymmetry(num))
cout << "yes" << endl;
else
cout << "no" << endl;
}
return 0;
}

bool isPrime(int num){
if (num == 1)
return false;//1不是素数
for(int i = 2; i <= sqrt(num*1.0); ++i)
if(num%i == 0)
return false;
return true;
}

bool isSymmetry(int num){
ostringstream oss;
oss << num;
string s = oss.str();
int i = 0;
int j = s.length() - 1;
bool flag = true;
while(i <= j){
if(s[i++] != s[j--]){
flag = false;
break;
}
}
return flag;
}