[LeetCode]Maximum Subarray

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.

DP问题，找到递推公式是关键。

local = max(local+nums[i],nums[i])

global = max(global,local)

这就是递推公式。

class Solution {
public:
    int maxSubArray(vector<int>& nums) {
        if(nums.size()==0) return 0;
        int global = nums[0],local=nums[0];
        for(int i=1;i<nums.size();i++)
        {
            local = max(local+nums[i],nums[i]);
            global = max(global,local);
        }
        return global;
    }
};