Given a natural number n, the task is to write a Python program to first find the sum of first n natural numbers and then print each step as a pattern.
Input: 5
Output:
1 = 1
1 + 2 = 3
1 + 2 + 3 = 6
1 + 2 + 3 + 4 = 10
1 + 2 + 3 + 4 + 5 = 15Input: 10
Output:
1 = 1
1 + 2 = 3
1 + 2 + 3 = 6
1 + 2 + 3 + 4 = 10
1 + 2 + 3 + 4 + 5 = 15
1 + 2 + 3 + 4 + 5 + 6 = 21
1 + 2 + 3 + 4 + 5 + 6 + 7 = 28
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 = 36
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = 45
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = 55
Approach:
- Take Input n.
- Use two loops:
- j ranging between 1 to n.
- i ranging between 1 to j.
- Print the value of i and ‘+’ operator while appending the value of i to a list.
- Then Find the Sum of Elements in the List.
- Print “=” with Total Sum.
- Exit.
Program:
Python3
# Inputing Natural Numbernumber = int(input("Enter the Natural Number: "))# j ranges from 1 to nfor j in range(1, number+1): # Initializing List a = [] # i loop ranges from 1 to j for i in range(1, j+1): print(i, sep=" ", end=" ") if(i < j): print("+", sep=" ", end=" ") a.append(i) print("=", sum(a))print() |
Output:
Enter the Natural Number: 5
1 = 1
1 + 2 = 3
1 + 2 + 3 = 6
1 + 2 + 3 + 4 = 10
1 + 2 + 3 + 4 + 5 = 15
Time Complexity: O(n2), where n represents the given input.
Auxiliary Space: O(1), no extra space is required, so it is a constant.
