Lintcode: Minimum Subarray 解题报告
Minimum Subarray
原题链接: http://lintcode.com/zh-cn/problem/minimum-subarray/#
Given an array of integers, find the subarray with smallest sum.
Return the sum of the subarray.
注意
The subarray should contain at least one integer.
样例
For [1, -1, -2, 1], return -3
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SOLUTION 1:
1. 我们把整个array * -1,把它转化为求最大和的题目。
2. 然后我们可以使用Sliding window的方法来做。记录一个sum,如果发现sum<0 则丢弃,否则不断把当前的值累加到sum,
3. 每计算一次sum,求一次max.
4. 返回-max即可。
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
1 public class Solution { 2 /** 3 * @param nums: a list of integers 4 * @return: A integer indicate the sum of minimum subarray 5 */ 6 public int minSubArray(ArrayList<Integer> nums) { 7 // write your code 8 9 int len = nums.size(); 10 11 int max = Integer.MIN_VALUE; 12 int sum = 0; 13 for (int i = 0; i < len; i++) { 14 if (sum < 0) { 15 sum = -nums.get(i); 16 } else { 17 sum += -nums.get(i); 18 } 19 20 max = Math.max(max, sum); 21 } 22 23 return -max; 24 } 25 }
GITHUB:
https://github.com/yuzhangcmu/LeetCode_algorithm/blob/master/lintcode/array/SubarraySum.java
posted on 2014-12-19 18:26 Yu's Garden 阅读(641) 评论(0) 编辑 收藏 举报