53. Maximum Subarray

Kadane's Algorithm

對於新的元素有兩個選擇：

• 選：curSum + num
• 不選：num

Solution

class Solution {
public:
    int maxSubArray(vector<int>& nums) {
        int curSum = 0;
        int maxSum = INT_MIN;
        for (int num : nums)
        {
            curSum = max(num, curSum + num);
            maxSum = max(maxSum, curSum);
        }
        return maxSum;
    }
};

• 時間複雜度：
  $O(N)$
• 空間複雜度：
  $O(1)$