Algorithm
Problem Name: 561. Array Partition
Problem Link: https://leetcode.com/problems/array-partition/
Given an integer array nums of 2n integers, group these integers into n pairs (a1, b1), (a2, b2), ..., (an, bn) such that the sum of min(ai, bi) for all i is maximized. Return the maximized sum.
Example 1:
Input: nums = [1,4,3,2] Output: 4 Explanation: All possible pairings (ignoring the ordering of elements) are: 1. (1, 4), (2, 3) -> min(1, 4) + min(2, 3) = 1 + 2 = 3 2. (1, 3), (2, 4) -> min(1, 3) + min(2, 4) = 1 + 2 = 3 3. (1, 2), (3, 4) -> min(1, 2) + min(3, 4) = 1 + 3 = 4 So the maximum possible sum is 4.
Example 2:
Input: nums = [6,2,6,5,1,2] Output: 9 Explanation: The optimal pairing is (2, 1), (2, 5), (6, 6). min(2, 1) + min(2, 5) + min(6, 6) = 1 + 2 + 6 = 9.
Constraints:
1 <= n <= 104nums.length == 2 * n-104 <= nums[i] <= 104
Code Examples
#1 Code Example with Python Programming
Code -
Python Programming
class Solution:
def arrayPairSum(self, nums):
"""
:type nums: List[int]
:rtype: int
"""
nums.sort()
sum=0
while nums:
num1=nums.pop()
num2=nums.pop()
sum+=num2
return sum
Input
nums = [1,4,3,2]
Output
4
#2 Code Example with C# Programming
Code -
C# Programming
using System;
namespace LeetCode
{
public class _0561_ArrayPartitionI
{
public int ArrayPairSum(int[] nums)
{
Array.Sort(nums);
int sum = 0;
for (var i = 0; i < nums.Length; i += 2)
sum += nums[i];
return sum;
}
}
}
Input
nums = [1,4,3,2]
Output
4