2000. Reverse Prefix of Word

class Solution {
public:
    string reversePrefix(string word, char ch) {
        int n = word.size(), ans=0;
        for(int i=0; i<n ; i++)
        {
            if(word[i]==ch)
              {
                  ans=i;
                  break;
              }
        }
        int i=0, j=ans;
        while(i<j)
        {
            swap(word[i], word[j] );
            i++;
            j--;
        }
        return word;
    }
};