LeetCode-209.Minimum Size Subarray Sum
Given an array of n positive integers and a positive integer s, find the minimal length of a contiguous subarray of which the sum ≥ s. If there isn't one, return 0 instead.
Example:
Input:s = 7, nums = [2,3,1,2,4,3]
Output: 2 Explanation: the subarray[4,3]
has the minimal length under the problem constraint.
Follow up:
If you have figured out the O(n) solution, try coding another solution of which the time complexity is O(n log n).
使用双指针,记录当前位置,和开始位置,通过移动两个指针,滑动窗口,时间复杂度O(n)
public int minSubArrayLen(int s, int[] nums) {//my int sum =0; int index = 0;//当前子序列开始的位置 int len =nums.length+1;//最小长度 for(int i =0;i<nums.length;i++){ sum += nums[i]; while(sum>=s){//如果sum>=s则左指针向右滑动 if((i-index+1)<len){ len = i-index+1; } sum -= nums[index]; index++; } } return len>nums.length?0:len; }