原题链接在这里:https://leetcode.com/problems/two-sum-less-than-k/
题目:
Given an array A
of integers and integer K
, return the maximum S
such that there exists i < j
with A[i] + A[j] = S
and S < K
. If no i, j
exist satisfying this equation, return -1.
Example 1:
Input: A = [34,23,1,24,75,33,54,8], K = 60 Output: 58 Explanation: We can use 34 and 24 to sum 58 which is less than 60.
Example 2:
Input: A = [10,20,30], K = 15 Output: -1 Explanation: In this case it‘s not possible to get a pair sum less that 15.
Note:
1 <= A.length <= 100
1 <= A[i] <= 1000
1 <= K <= 2000
题解:
Sort the array. Use two pointers pointing at head and tail. Calculate the sum.
If sum < K, update res and l++ to increase sum.
Otherwise, r-- to decrease sum.
Time Complexity: O(nlogn). n = A.length.
Space: O(1).
AC Java:
1 class Solution { 2 public int twoSumLessThanK(int[] A, int K) { 3 int res = -1; 4 if(A == null || A.length == 0){ 5 return res; 6 } 7 8 Arrays.sort(A); 9 int l = 0; 10 int r = A.length-1; 11 while(l<r){ 12 int sum = A[l] + A[r]; 13 if(sum < K){ 14 res = Math.max(res, sum); 15 l++; 16 }else{ 17 r--; 18 } 19 } 20 21 return res; 22 } 23 }
类似Subarray Product Less Than K.
原文地址:https://www.cnblogs.com/Dylan-Java-NYC/p/11368115.html
时间: 2024-10-10 17:16:27