remove k digits - Dec 29, 2019 10:00 PM - mock interview as an interviewer, the interviewee finished boot camp in New York.

removeKDigits.js

const removeKdigits = (nums, k) => {
  
  if(!nums.length) return;
  else if(k === 0) return Number(nums.join(''));
  
  
  let lowest = Infinity;
  
  const helper = (idx, strArr, r) => {
    
    if(r === k) {
      strArr = strArr.concat(nums.slice(idx));
      const n = Number(strArr.join(''))
      lowest = lowest > n ? n : lowest;  /* compare to lowest one */
    };
    
    for(let i=idx; i<nums.length; i+=1) {
      helper(i + 1, [...strArr], r + 1); 
      strArr.push(nums[i]);
    };
  };

  helper(0, [], 0);
  return lowest;
};

console.log(removeKdigits("1432219", 3));
console.log(removeKdigits("10", 2));
console.log(removeKdigits("10200", 1));