【Leetcode】最大子序和

class Solution {
public:
    int maxSubArray(vector<int>& nums) {
        if(nums.size() == 0)
            return -1;
        
        return getMaxSub(nums, 0);
    }
    
    int getMaxSub(const vector<int>& vecInt, int index) {
        
        int maxR = vecInt[index], sum = 0;
        
        for(index; index < vecInt.size(); ++index) {
            sum = sum + vecInt[index];
            
            if(sum <= 0 && index < (vecInt.size() - 1)) {  // 确保下一级序列非空
                maxR = max(maxR, getMaxSub(vecInt, index+1));
                return maxR;
            }
            else {
                maxR = max(maxR, sum);
            }
        }
        return maxR;
    }
};