Find the number of sum pairs for the given number

Question

Accepted Answer

The question asks to find the number of sum pairs for a given number.

Iterate through the array and for each element, check if there is another element that sums up to the given number
Use a hash set to store the complement of each element as you iterate through the array
If the complement of an element is already in the hash set, increment the count of sum pairs

Accepted Answer

#include

// Naive method to find a pair in an array with a given sum

void findPair(int nums[], int n, int target)

{

// consider each element except the last

for (int i = 0; i < n - 1; i++)

{

// start from the i'th element until the last element

for (int j = i + 1; j < n; j++)

{

// if the desired sum is found, print it

if (nums[i] + nums[j] == target)

{

printf("Pair found (%d, %d) ", nums[i], nums[j]);

return;

}

// we reach here if the pair is not found

printf("Pair not found");

}

int main(void)

{

int nums[] = { 8, 7, 2, 5, 3, 1 };

int target = 10;

int n = sizeof(nums)/sizeof(nums[0]);

findPair(nums, n, target);

return 0;

}

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