[swift] LeetCode 53. Maximum Subarray

Find the contiguous subarray within an array (containing at least one number) which has the largest sum.

For example, given the array [−2,1,−3,4,−1,2,1,−5,4],

the contiguous subarray [4,−1,2,1] has the largest sum = 6.

click to show more practice.

More practice:

If you have figured out the O(n) solution, try coding another solution using the divide and conquer approach, which is more subtle.

func maxSubArray(_ nums: [Int]) -> Int {
    if nums.isEmpty { return 0 }
 
    var gMax = nums[0], lMax = nums[0]
    for i in 1..<nums.count {
        lMax = nums[i] + max(lMax, 0)
        gMax = max(gMax, lMax)
    }
 
    return gMax
}