[NOIP2011 普及组] 数字反转 洛谷P1307

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
int main()
{	
	int len;
	string a;
	while(cin>>a){	//连续输入直到按下回车 
		if(getchar() == '\n')
			break;
	}
	len = a.size();
	while(a[len-1] == '0')	//排除前导0的情况，如210-->012 
		len--;
	if(len)
	{
		if(a[0]=='-'){
			for(int i=1;i<len/2+1;i++)
			{
				int t = a[i];
				a[i] = a[len-i];
				a[len-i] = t;
			}
		}else{
			for(int i=0;i<(len+1)/2;i++)
			{
				int t = a[i];
				a[i] = a[len-1-i];
				a[len-1-i] = t;
			}
		}
		for(int i=0;i<len;i++)
			cout<<a[i];
		cout<<endl;
	}else{
		cout<<"0"<<endl;
	}
	
	return 0;
}