## Q. Write an algorithm and program to find all pairs of elements in an integer array whose sum is equal to a given number.

Solution : You are given an array and a number and task is to find all pairs of elements in an integer array whose sum is equal to a given number.

Array :- An array is a collection of data items, all of the same type, accessed using a common name.
For example: int arr[5]={1,2,3,4,5};

## Algorithm to find pairs of elements in an integer array

```//Algorithm To Find All Pairs Of Elements In An Integer Array.
START
Step 1 ->  Input ARRAY arr[] and NUMBER num.
Step 2 ->  for i=0 to length of the arr[]-1:
for j=i+1 to length of the arr[]:
if arr[i]+arr[j] equals to num:
print the output
Loop End
Loop End
STOP
```

# Program to find all pairs of elements in an integer array

• C
• C++
• Java
• Python
• C#
• PHP
• ```//C Program To Find All Pairs Of Elements In An Integer Array.
#include <stdio.h>
int main()
{
int arr[7]={4, 6, 8, 10, 12, 14, 16};
int num=18;
for(int i=0;i<6;i++)
{
for(int j=i+1;j<7;j++)
{
if((arr[i]+arr[j])==num)
{
printf("%d + %d = %d\n",arr[i],arr[j],num);
}
}
}
return 0;
}
```
```//C++ Program To Find All Pairs Of Elements In An Integer Array.
#include <iostream>
using namespace std;
int main()
{
int arr[7]={4, 6, 8, 10, 12, 14, 16};
int num=18;
for(int i=0;i<6;i++)
{
for(int j=i+1;j<7;j++)
{
if((arr[i]+arr[j])==num)
{
cout<<arr[i]<<" + "<<arr[j]<<" = "<<num<<"\n";
}
}
}
return 0;
} ```
```//Java Program To Find All Pairs Of Elements In An Integer Array.
import java.util.Arrays;
public class Main
{
public static void main(String[] args)
{
int arr[] = { 4, 6, 8, 10, 12, 14, 16 };
int num = 18;
for(int i=0;i<6;i++)
{
for(int j=i+1;j<7;j++)
{
if((arr[i]+arr[j])==num)
{
System.out.println(arr[i]+" + "+arr[j]+" = "+num);
}
}
}
}
}
```
```//Python Program To Find All Pairs Of Elements In An Integer Array.
arr = [ 4, 6, 8, 10, 12, 14, 16 ]
n = len(arr)
num = 18
for i in range(0, n):
for j in range(i+1, n):
if((arr[i]+arr[j])==num):
print(arr[i]," + ",arr[j]," = ",num)
```
```//C# Program To Find All Pairs Of Elements In An Integer Array.
using System;
class LFC {
static void Main() {
int[] arr = { 4, 6, 8, 10, 12, 14, 16 };
int num = 18;
for(int i=0;i<6;i++)
{
for(int j=i+1;j<7;j++)
{
if((arr[i]+arr[j])==num)
{
Console.WriteLine(arr[i]+" + "+arr[j]+" = "+num);
}
}
}
}
} ```
```//PHP Program To Find All Pairs Of Elements In An Integer Array.
<?php
\$arr = array(4, 6, 8, 10, 12, 14, 16);
\$num = 18;
for(\$i=0;\$i<6;\$i++)
{
for(\$j=\$i+1;\$j<7;\$j++)
{
if((\$arr[\$i]+\$arr[\$j])==\$num)
{
echo "\$arr[\$i] + \$arr[\$j] = \$num\n";
}
}
}?>```
```//C Program To Find All Pairs Of Elements In An Integer Array.
#include <stdio.h>
int main()
{
int arr[7]={4, 6, 8, 10, 12, 14, 16};
int num=18;
for(int i=0;i<6;i++)
{
for(int j=i+1;j<7;j++)
{
if((arr[i]+arr[j])==num)
{
printf("%d + %d = %d\n",arr[i],arr[j],num);
}
}
}
return 0;
}
```

#### Output

```4 + 14 = 18
6 + 12 = 18
8 + 10 = 18
```

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