/**

• @param {string} s

• @param {number[]} spaces

• @return {string}
  */
  var addSpaces = function(s, spaces) {
  var joined;
  for(j=spaces.length-1;j>=0;j--){
  joined=s.substring(0,spaces[j]).concat(' ');
  s= joined.concat(s.substring(spaces[j],s.length));
  //console.log(s);

  }
  //console.log(s);
  return s;

};