# Find 2 elements of an array with sum equals zero with example in c,c++,python and java

I’ll provide solutions for finding two elements in an array whose sum equals zero in C, C++, Python, and Java.

1. Solution in C:
```#include <stdio.h>

void findElements(int arr[], int n) {
for (int i = 0; i < n; i++) {
for (int j = i + 1; j < n; j++) {
if (arr[i] + arr[j] == 0) {
printf("Pair found: %d and %dn", arr[i], arr[j]);
return;
}
}
}
printf("No pair found.n");
}

int main() {
int arr[] = {2, -5, 7, -3, 1};
int size = sizeof(arr) / sizeof(arr[0]);

findElements(arr, size);

return 0;
}

```
1. Solution in C++:
```#include <iostream>
#include <unordered_set>

void findElements(int arr[], int n) {
std::unordered_set<int> elements;

for (int i = 0; i < n; i++) {
int complement = -arr[i];
if (elements.count(complement)) {
std::cout << "Pair found: " << arr[i] << " and " << complement << std::endl;
return;
}
elements.insert(arr[i]);
}

std::cout << "No pair found." << std::endl;
}

int main() {
int arr[] = {2, -5, 7, -3, 1};
int size = sizeof(arr) / sizeof(arr[0]);

findElements(arr, size);

return 0;
}

```
1. Solution in Python:
```def find_elements(arr):
elements = set()

for num in arr:
complement = -num
if complement in elements:
print("Pair found:", num, "and", complement)
return

print("No pair found.")

arr = [2, -5, 7, -3, 1]
find_elements(arr)

```
1. Solution in Java:
```import java.util.HashSet;

class Main {
static void findElements(int[] arr) {
HashSet<Integer> elements = new HashSet<>();

for (int num : arr) {
int complement = -num;
if (elements.contains(complement)) {
System.out.println("Pair found: " + num + " and " + complement);
return;
}
}

System.out.println("No pair found.");
}

public static void main(String[] args) {
int[] arr = {2, -5, 7, -3, 1};
findElements(arr);
}
}

```

These solutions iterate over the array and use different techniques to find two elements whose sum is zero. The C and C++ solutions use nested loops and an unordered set, while the Python and Java solutions utilize a set or HashSet to store the elements and check for the existence of the complement.