two-sum-less-than-k

< Previous 　　　　　　　　　　　　　　　　 Next >

1099. Two Sum Less Than K (Easy)

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. 1 <= A.length <= 100
2. 1 <= A[i] <= 1000
3. 1 <= K <= 2000

Related Topics

[Array] [Two Pointers] [Binary Search] [Sorting]

Similar Questions

1. Two Sum (Easy)
2. Two Sum II - Input Array Is Sorted (Easy)
3. 3Sum Smaller (Medium)
4. Subarray Product Less Than K (Medium)

Hints

Hint 1

What if we have the array sorted?

Hint 2

Loop the array and get the value A[i] then we need to find a value A[j] such that A[i] + A[j] < K which means A[j] < K - A[i]. In order to do that we can find that value with a binary search.