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：就是求最大字数组和。
思路：
DP问题，O(n)内可破
对于位置arr[0]~arr[i]，最大字数组和
arr[0] i==0
maxSum[i]=
max{ maxSum[i-1]+arr[i] , arr[i] } 0<i<arr.length
具体来说该题没必要采用maxSum数组，用一个变量记住最大字数组和即可。
Java代码如下：
public class Solution {
public int maxSubArray(int[] nums) {
int max = nums[0],maxEndingHere = nums[0];
for (int i = 1; i < nums.length; i++) {
maxEndingHere = Math.max(maxEndingHere+nums[i],nums[i]);
max = Math.max(maxEndingHere,max);
}
return max;
}
}