输入两个数输出之间的回文数

输入两个数输出之间的回文数：

bool A(int num) {
    
    
    if (num >= 0 && num < 10) return true;
    if (num%10==0) return false;
    int num1 = num, num2 = 0;
    while (num2 < num1 && num2 != num1) {
    
    
        num2 = num2 * 10 + (num1 % 10);
        num1 /= 10;
        //cout << num1 << ", " << num2 <<endl;
    }
    return num1 == num2 || num1 == num2 / 10;
}

int main(void){
    
    
    int le, ri;
    cin >> le >> ri;
    for (int i = le; i < ri; i ++) {
    
    
        if (A(i))
            cout << i <<endl;
    }
    return 0;
}

判断素数：（与题目无关）
for(int i=2; i<=sqrt(n); i++){
    
    
        if(n%i == 0){
    
    
            cout << n << " isn't a prime" << endl;
            return 1;
        }