Sixteen LeetCode of problem solving: the largest and subsequence

topic

Given an array of integers nums, and find a maximum sub-arrays having a continuous (subarray least one element), and to return to its maximum.

Examples

输入: [-2,1,-3,4,-1,2,1,-5,4],
输出: 6
解释: 连续子数组 [4,-1,2,1] 的和最大，为 6

answer

public class Solution {
    public int maxSubArray(int[] A) {
        if (A == null || A.length == 0){
            return 0;
        }
        //max记录全局最大值，sum记录前i个数的和，minSum记录前i个数中0-k的最小值
        int max = Integer.MIN_VALUE, sum = 0, minSum = 0;
        for (int i = 0; i < A.length; i++) {
            sum += A[i];
            max = Math.max(max, sum - minSum);
            minSum = Math.min(minSum, sum);
        }

        return max;
    }
}