Case study: remove k digits - DFS algorithm using JavaScript

Dec. 29, 2019

Introduction

It is my first Sunday 10:00 am mock interview. I like to write a short case study on this mock interview.

Case study

I will add more content later.

	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));

view raw removeKDigits.js hosted with ❤ by GitHub