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] <= 104program main
implicit none
integer, parameter :: n = 2
integer, parameter :: nums(2*n) = [1, 4, 3, 2, 6, 2, 6, 5, 1, 2]
integer :: i, j, k
integer :: min_val
integer :: max_sum
! Initialize variables
max_sum = 0
! Loop over all possible pairs
do i = 1, n
do j = i+1, n
min_val = min(nums(i), nums(j))
max_sum = max(max_sum, min_val)
end do
end do
print '(I0)', max_sum
end program maintemp.f95:5:35:
5 | integer, parameter :: nums(2*n) = [1, 4, 3, 2, 6, 2, 6, 5, 1, 2]
| 1
Error: Different shape for array assignment at (1) on dimension 1 (4 and 10)
temp.f95:16:26:
16 | min_val = min(nums(i), nums(j))
| 1
Error: Function ‘nums’ at (1) has no IMPLICIT type
module pair_sum
implicit none
contains
function pair_sum_max(nums) result(max_sum)
! 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 <= 104
! nums.length == 2 * n
! -104 <= nums[i] <= 104
integer, intent(in) :: nums(:)
integer :: max_sum, i, j, min_val
! Initialize the maximum sum to 0
max_sum = 0
! Loop through the array in pairs
do i = 1, size(nums), 2
! Calculate the minimum value of the two elements in the pair
min_val = min(nums(i), nums(i+1))
! Add the minimum value to the maximum sum
max_sum = max_sum + min_val
end do
end function pair_sum_max
end module pair_sum
program test_pair_sum
use pair_sum, only : pair_sum_max
implicit none
! Test case 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.
call assert(pair_sum_max([1,4,3,2]) == 4)
! Test case 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.
call assert(pair_sum_max([6,2,6,5,1,2]) == 9)
contains
subroutine assert(condition)
logical, intent(in) :: condition
if (.not. condition) then
write (*,*) "Assertion failed"
stop 1
end if
end subroutine assert
end program test_pair_sum
Assertion failed
STOP 1
def array_pair_sum(nums):
nums.sort()
return sum(nums[::2])
#include <vector>
#include <algorithm>
int arrayPairSum(std::vector<int>& nums) {
std::sort(nums.begin(), nums.end());
int sum = 0;
for (int i = 0; i < nums.size(); i += 2) {
sum += nums[i];
}
return sum;
}