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| 标题： | Maximum Subarray |
| 通过率： | 34.5% |
| 难度： | 中等 |
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.
本题就是求最大字段和，算法设计的基础算法。动态规划
公式解读：B[i]为到位置i时的最大字段和，A[i]为第i个位置的元素
那么B[k]=max{a[k],B[k-1]+A[k]}
java代码如下：
1 public class Solution { 2 public int maxSubArray(int[] A) { 3 int sum=A[0],tmp=A[0]; 4 for(int i=1;i<A.length;i++){ 5 if(tmp>0){ 6 tmp+=A[i]; 7 } 8 else{ 9 tmp=A[i]; 10 } 11 if(tmp>sum){ 12 sum=tmp; 13 } 14 } 15 return sum; 16 } 17 }
python代码如下：
1 class Solution: 2 # @param A, a list of integers 3 # @return an integer 4 def maxSubArray(self, A): 5 # kadane‘s dynamic programming algorithm 6 maxSum = -1 * (1 << 30) 7 currSum = maxSum 8 for a in A: 9 currSum = max(a, a + currSum) 10 maxSum = max(maxSum, currSum) 11 return maxSum
leetcode------Maximum Subarray
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原文地址：http://www.cnblogs.com/pkuYang/p/4289976.html
