LeetCode: Maximum Subarray 解题报告

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.

SOLUTION 1:

采用滑动窗口解决。sum 如果小于0，置为0，再加上当前值。

然后再与max相比，取大的。 1分钟AC

 public class Solution {
     public int maxSubArray(int[] A) {
         if (A == null || A.length == 0) {
             return 0;
         }

         int max = Integer.MIN_VALUE;
         int sum = 0;

         int len = A.length;
         for (int i = 0; i < len; i++) {
             if (sum < 0) {
                 sum = 0;
             }

             sum += A[i];
             max = Math.max(max, sum);
         }

         return max;
     }
 }

https://github.com/yuzhangcmu/LeetCode_algorithm/blob/master/array/MaxSubArray_1220_2014.java