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.
题意：找到最大公共数组
目前时间复杂度O(n)，这个可以降低到log(n)，日后再优化：
java代码：
public int maxSubArray(int[] nums) {
int result = nums[0];
int max = nums[0];
for (int i = 1; i < nums.length; i++) {
if (max + nums[i] < nums[i]) max = nums[i];
else max = max + nums[i];
if (max > result) result = max;
}
return result;
}
