string类属于STL，可以用reverse和begin()、end()函数 另外stringstream用在此处也很方便

#include <iostream>
#include <cstring>
#include <algorithm>
#include <sstream>

using namespace std;

string str, out, temp;

int main()
{
    getline(cin, str);
    
    stringstream ssin(str);
    
    while(ssin >> temp) {
        reverse(temp.begin(), temp.end());
        out += temp; out += ' ';
    }
    
    cout << out << endl;
    
    return 0;
}