53. 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.

 1 class Solution {
 2 public:
 3     int maxSubArray(vector<int>& nums) {
 4         if(nums.size() == 0){
 5             return 0;
 6         }
 7         
 8         int sum = 0;
 9         int greatSum = INT_MIN;
10         
11         for(int i = 0; i < nums.size() ; i++){
12             sum += nums[i];
13             greatSum = max(greatSum, sum);
14             if(sum < 0){
15                 sum = 0;
16             }
17         }
18         return greatSum;
19     }
20 };