title: Replace Character C1 C2 C2 C1 String S
signature: function replace_character_c1_c2_c2_c1_string_s(s, c1, c2)
source_py: def replace_character_c1_c2_c2_c1_string_s(s, c1, c2):
      l = len(s)
      for i in range(l):
          if (s[i] == c1):
              s = ((s[0:i] + c2) + s[(i + 1):])
          elif (s[i] == c2):
              s = ((s[0:i] + c1) + s[(i + 1):])
      return s
source_cpp: string replace_character_c1_c2_c2_c1_string_s(string s, char c1, char c2) {
    int l = s . length ( );
    for ( int i = 0;
    i < l;
    i ++ ) {
      if ( s [ i ] == c1 ) s [ i ] = c2;
      else if ( s [ i ] == c2 ) s [ i ] = c1;
    }
    return s;
  }