原题链接在这里:https://leetcode.com/problems/number-of-subarrays-with-bounded-maximum/
题目:
Given an integer array nums
and two integers left
and right
, return the number of contiguous non-empty subarrays such that the value of the maximum array element in that subarray is in the range [left, right]
.
The test cases are generated so that the answer will fit in a 32-bit integer.
Example 1:
Input: nums = [2,1,4,3], left = 2, right = 3 Output: 3 Explanation: There are three subarrays that meet the requirements: [2], [2, 1], [3].
Example 2:
Input: nums = [2,9,2,5,6], left = 2, right = 8 Output: 7
Constraints:
1 <= nums.length <= 105
0 <= nums[i] <= 109
0 <= left <= right <= 109
题解:
When iterate to current num, if num > right, then the subarray ending with num is not valid. set prev = i + 1.
If num is within [left, right], then we find a valid subarray ending with num, the start index of subarray is prev. Accumlate the count i - prev + 1 to the result.
Time Complexity: O(n). n = nums.length.
Space: O(1).
AC Java:
1 class Solution { 2 public int numSubarrayBoundedMax(int[] nums, int left, int right) { 3 int n = nums.length; 4 int prev = 0; 5 int count = 0; 6 int res = 0; 7 for(int i = 0; i < n; i++){ 8 if(nums[i] > right){ 9 count = 0; 10 prev = i + 1; 11 }else if(nums[i] >= left){ 12 count = i - prev + 1; 13 } 14 15 res += count; 16 } 17 18 return res; 19 } 20 }
跟上Count Subarrays With Fixed Bounds.
标签:count,795,right,nums,int,Subarrays,Maximum,prev,left From: https://www.cnblogs.com/Dylan-Java-NYC/p/16796183.html