Implementation of String methods that makes the following main function working without any logical/ compile errors. int main(){ char first[100], second[100], third[100]; int len, end , ok; char ch; cout << "Enter a string: "; gets_s( first) ; len = length(first); end = len / 2; ok = substring(first , second, 0,end); ok = substring(first , third, end+1,len-1); append(third , second); copy(first , third ); cout << " New version of string: "; cout << endl << first << endl << endl; ok = at(first , 3 , ch); if (ok) cout << "The 4th char of the new string is "<< ch << endl; else cout << "The new string has less than 4 char "; ok = find(first , 'a'); if (ok != -1) cout << "The first place a was found is loc "<< ok << endl; else cout << "There was no a in the new string "; } Output: Enter a string: we wouldn't have to walk to the store New version of string: walk to the storewe wouldn't have to The 4th char of the new string is k The first place a was found is in loc 1