Find all pairs on integer array whose sum is equal to given number

April 21, 2022

pair with given sum in python

Pairs with given sum in Python

We will get an array as input from user. We need to find all possible pairs from the given array whose sum is same as given sum. 

Example:

  • Array :   [5, 2, 3, 4, 1, 6, 7]
  • Sum= 7
  • Possible pairs:  [5, 2], [3, 4], [1, 6]

Algorithm

  • Step 1: Initialize array and its values
  • Step 2: Initialize value of sum
  • Step 3: Call the function find

Algorithm for function find

  • Step 1: Iterate on the elements of array with variable i, from 0 to length of array.

                 1. For each value of i iterate on array from index i till length of array using variable j.

                 2. Check if array[i]+array[j] ==given sum.

                  3. If the above(2) condition is true then print the pairs

python program to find pairs with given sum

Python Code

Run 
def find(array, len, summ):
    print("Pairs whose sum is : ", summ)
    for i in range(len):
        for j in range(i, len):
            if (array[i] + array[j]) == summ:
                print(array[i], array[j])


array = [5, 2, 3, 4, 1, 6, 7]

# Take sum as input from user
summ = 7

# print array
print("Array= ", array)

# call function find
find(array, len(array), summ)

Output

Array= [5, 2, 3, 4, 1, 6, 7]
Pairs whose sum is : 7
5 2
3 4
1 6