Input:  “she is my sister” 
Output:  “he is my brother”.
There are two gender-specific words in this
sentence:“she” and “sister”. After toggling
gender specific words to their respective 
counterparts - “he” and “brother” :
Gender specific words of the string are now 
changed.

// A C++ Program to change the gender of a string
#include<bits/stdc++.h>
using namespace std;

// A Function that returns the new string with gender
// changed
string changeGender(string str)
{
    // A Dictionary to store the mapping of genders
    // The user can add his words too.
    unordered_multimap <string, string> dictionary =
    {
      {"batman", "batwoman"}, {"batwoman", "batman"},
      {"boy", "girl"}, {"girl", "boy"},
      {"boyfriend", "girlfriend"}, {"girlfriend", "boyfriend"},
      {"father", "mother"}, {"mother", "father"},
      {"husband", "wife"}, {"wife", "husband"},
      {"he", "she"}, {"she", "he"},
      {"his", "her"}, {"her", "his"},
      {"male", "female"}, {"female", "male"},
      {"man", "woman"}, {"woman", "man"},
      {"Mr", "Ms"}, {"Mr", "Ms"},
      {"sir", "madam"}, {"madam", "sir"},
      {"son", "daughter"}, {"daughter", "son"},
      {"uncle", "aunt"}, {"aunt", "uncle"},
    };

    str = str + ' '; // Append a space at the end

    int n = str.length();

    // 'temp' string will hold the intermediate words
    // and 'ans' string will be our result
    string temp = "", ans = "";

    for (int i=0; i<=n-1; i++)
    {
        if (str[i] != ' ')
            temp.push_back(str[i]);
        else
        {
            // If this is a 'male' or a 'female' word then
            // swap this with its counterpart
            if (dictionary.find(temp) != dictionary.end())
                temp = dictionary.find(temp)->second;

            ans = ans + temp + ' ';
            temp.clear();
        }
    }

    return(ans);
}

// Driver Program to test above functions
int main()
{
    string str = "she is going to watch movie with"
                " her boyfriend";

    cout << changeGender(str);

    return (0);
}