Question

How to find pairs in an array with a given difference N between them in C++

Answer 1

#include <iostream>
#include <unordered_set>

void findPairs(int arr[], int size, int diff) {
    std::unordered_set<int> set;
 
    for (int i = 0; i < size; i++) {
        if (set.find(arr[i] - diff) != set.end()) {
            std::cout << arr[i] << ", " << arr[i] - diff << "\n";
        }
 
        if (set.find(arr[i] + diff) != set.end()) {
            std::cout << arr[i] + diff << ", " << arr[i] << "\n";
        }
 
        set.insert(arr[i]);
    }
}
 
int main()
{
    int arr[] = { 4, 1, 7, 5, 8, 6, 9, 10 };
    int diff = 3;
 
    findPairs(arr, sizeof(arr) / sizeof(arr[0]), diff);
}




/*
run:

4, 1
7, 4
8, 5
9, 6
10, 7

*/

 

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