字符串反转

#include <iostream>
#include <stdio.h>
#include <vector>
using namespace std;
int main()
{
    int ch;
    vector<char> vec;
    while((ch=getchar())&& ch != '\n')
    {
        vec.push_back(ch);
    }
    while(!vec.empty())
    {
        printf("%c",vec.back());
        vec.pop_back();
    }
    return 0;
}