Given an integer array nums, find the subarray with the largest sum, and return its sum.
Example 1:
Input: nums = [-2,1,-3,4,-1,2,1,-5,4] Output: 6 Explanation: The subarray [4,-1,2,1] has the largest sum 6.
Example 2:
Input: nums = [1] Output: 1 Explanation: The subarray [1] has the largest sum 1.
Example 3:
Input: nums = [5,4,-1,7,8] Output: 23 Explanation: The subarray [5,4,-1,7,8] has the largest sum 23.
Constraints:
1 <= nums.length <= 105-104 <= nums[i] <= 104
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.
class Solution {
public int maxSubArray(int[] nums) {
int cumsum = 0, maxm = -Integer.MIN_VALUE;
for (int lt = 0, rt = 0; rt < nums.length; rt++) {
while (cumsum < 0 && lt <= rt)
cumsum -= nums[lt++];
cumsum += nums[rt];
// System.out.println(cumsum + "\t->" + nums[lt] + "\t" + nums[rt]);
maxm = Math.max(cumsum, maxm);
}
return maxm;
}
}