1679. Max Number of K-Sum Pairs¶
Tags: #array #twopointers #sorting #hashtable #medium
Problem Statement¶
You are given an integer array nums and an integer k.
In one operation, you can pick two numbers from the array whose sum equals k and remove them from the array.
Return the maximum number of operations you can perform on the array.
Input: nums = [1,2,3,4], k = 5
Output: 2
Explanation: Starting with nums = [1,2,3,4]:
- Remove numbers 1 and 4, then nums = [2,3]
- Remove numbers 2 and 3, then nums = []
There are no more pairs that sum up to 5, hence a total of 2 operations.
My Approach¶
class Solution:
def maxOperations(self, nums: List[int], k: int) -> int:
i = 0
j = len(nums)-1
count = 0
nums.sort()
while(i<j):
sum =nums[i]+nums[j]
if sum == k:
count +=1
i+=1
j-=1
elif sum < k:
i+=1
else:
j-=1
return count