[NOIP 2011 普及组 T1] 数字反转
#include <bits/stdc++.h>
using namespace std;
int main()
{
int n, m = 0, flag;
cin >> n;
if (n < 0)
{
n *= -1;
flag = -1;
}
else
flag = 1;
while (n)
{
m = m * 10 + n % 10;
n /= 10;
}
cout << m *flag << endl;
return 0;
}其实，从数学的角度看，不用考虑符号，整数范围内都是一样的：
#include <bits/stdc++.h>
using namespace std;
int main()
{
int n, m = 0, flag;
cin >> n;
while (n)
{
m = m * 10 + n % 10;
n /= 10;
}
cout << m << endl;
return 0;
}