Maximun_Subarray.js

/*
Maximum Subarray
https://leetcode.com/problems/maximum-subarray

Given an integer array nums, find the contiguous subarray (containing at least one number) 
which has the largest sum and return its sum.

Example:

Input: [-2,1,-3,4,-1,2,1,-5,4],
Output: 6
Explanation: [4,-1,2,1] has the largest sum = 6.
Follow up:

*/

var maxSubArray = function (nums) {
  if (nums.length == 0) return 0;
  var maxSub = nums[0];
  var currentMax = nums[0];

  for (var i = 1; i < nums.length; i++) {
    currentMax = max(nums[i], currentMax + nums[i]);
    if (currentMax > maxSub) maxSub = currentMax;
  }

  return maxSub;
};

var max = function (i, j) {
  return i > j ? i : j;
};

module.exports.maxSubArray = maxSubArray;