题目描述：
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.
思路：
用sum保存连续序列之和，用max表示最大值，一次遍历即可，时间复杂度O(n)。
- sum<0,则舍弃前面的数
- sum>max,则更新最大值max
代码实现：
int maxSubArray(int* nums, int numsSize) {
int sum=0;
int max=INT_MIN;
for(int i=0;i<numsSize;i++){
sum+=nums[i];
if(sum>max){
max = sum;
}
if(sum<0){
sum = 0;
}
}
return max;
}