回文数判定题解

学生版：

#include<bits/stdc++.h>
#include <ostream>
using namespace std;
bool is(int x) {
    int sum=0;
    int t=x;
    while(x) {
        sum=sum*10+x%10;
        x/=10;
    }
    if(sum==t) return true;
    else return false;
}
int main()
{
    int n;
    cin>>n;
    if(is(n)) cout<<"Yes"<<endl;
    else cout<<"No"<<endl;
    return 0;
}

老师版：

#include <bits/stdc++.h>
using namespace std;

bool isPal(int n)
{
    int temp = n;
    int reverse = 0;
    while (temp != 0)
    {
        reverse = reverse * 10 + temp % 10;
        temp /= 10;
    }
    if (reverse == n)
        return true;
    else
        return false;
}

int main()
{
    int n;
    cin >> n;
    if (isPal(n))
        cout << "Yes";
    else
        cout << "No";

    return 0;
}

简略版：

#include <bits/stdc++.h>
using namespace std;

bool ispal(string s)
{
    int n = s.size();
    for (int i = 0; i < n / 2; i++)
    {
        if (s[i] != s[n - i - 1])
        {
            return false;
        }
    }
    return true;
}

int main()
{
    string s;
    cin >> s;
    if (ispal(s))
        cout << "Yes";
    else
        cout << "No";

    return 0;
}