[LeetCode]209. Minimum Size Subarray Sum

Problem Description

Given an array of n positive integers and a positive integer s, find the minimal length of a subarray of which the sum ≥ s. If there isn’t one, return 0 instead.

For example, given the array [2,3,1,2,4,3] and s = 7,
the subarray [4,3] has the minimal length under the problem constraint.
[https://leetcode.com/problems/minimum-size-subarray-sum/]

思路

俩指针，一个在前面一个在后面，计算中间的和，如果小就把后指针向后移，如果大就把前指针向后移。
就酱！

Code

package q209;public class Solution {    public static int minSubArrayLen(int s, int[] nums) {        int minLen=Integer.MAX_VALUE;        int i=0,j=0;        int sum=0;        if(nums.length<1) return 0;        while(i<nums.length){            if(j>=nums.length&&sum<s) break;            while(j<nums.length&&sum<s){                sum=sum+nums[j];                j++;            }            if(sum>=s){                sum=sum-nums[i];                minLen=Math.min(minLen, j-i);                i++;            }        }        if(minLen==Integer.MAX_VALUE) return 0;        return minLen;    }//  public static void main(String[] args) {//      int[] a={1,2,3,4,5};//      System.out.print(minSubArrayLen(11,a));//  }}