LeetCode_53. Maximum Subarray

53. Maximum Subarray

Easy

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:

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

package leetcode.easy;

public class MaximumSubarray {
	@org.junit.Test
	public void test() {
		int[] nums = { -2, 1, -3, 4, -1, 2, 1, -5, 4 };
		System.out.println(maxSubArray(nums));
	}

	public int maxSubArray(int[] nums) {
		int max = nums[0];
		int count = 0;
		for (int i = 0; i < nums.length; i++) {
			if (nums[i] > max) {
				max = nums[i];
			}
			count = nums[i];
			for (int j = i + 1; j < nums.length; j++) {
				count += nums[j];
				if (count > max) {
					max = count;
				}
			}
		}
		return max;
	}
}