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Pascal’s Triangle

Certification: Basic Level Accuracy: 66.67% Submissions: 3 Points: 10

Write a C++ program to print Pascal's triangle up to the given number of rows n.

Example 1
    

  • Input: n = 5
    • 

  • Output: 
    
1
    
1 1
    
1 2 1
    
1 3 3 1
    
1 4 6 4 1
    • 

  • Explanation: 
      

    • Step 1: First row of Pascal's triangle is always [1].
      • 

    • Step 2: For subsequent rows, each element is the sum of the two elements above it.
      • 

    • Step 3: For row 2, we get [1, 1].
      • 

    • Step 4: For row 3, we calculate [1, 1+1, 1] = [1, 2, 1].
      • 

    • Step 5: For row 4, we calculate [1, 1+2, 2+1, 1] = [1, 3, 3, 1].
      • 

    • Step 6: For row 5, we calculate [1, 1+3, 3+3, 3+1, 1] = [1, 4, 6, 4, 1].
      • 

    • Step 7: Print all rows up to n = 5.
      • 

    •
Example 2
    

  • Input: n = 3
    • 

  • Output: 
    
1
    
1 1
    
1 2 1
    • 

  • Explanation: 
      

    • Step 1: First row of Pascal's triangle is always [1].
      • 

    • Step 2: For subsequent rows, each element is the sum of the two elements above it.
      • 

    • Step 3: For row 2, we get [1, 1].
      • 

    • Step 4: For row 3, we calculate [1, 1+1, 1] = [1, 2, 1].
      • 

    • Step 5: Print all rows up to n = 3.
      • 

    •
Constraints
    

  • 1 ≤ n ≤ 20
    • 

  • Time Complexity: O(n²)
    • 

  • Space Complexity: O(n²)
    •
NumberControl StructuresGoogleGoldman Sachs
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Hint
Solution

Solution Hints

    
  
  • Use nested loops to compute each element based on combinations.
    • 
  
  • Each element in a row can be derived from the previous element.
    •

Steps to solve by this approach:

 Step 1: Create a 2D array to store the triangle values.

 Step 2: Iterate through each row from 0 to n-1.

 Step 3: For each row, iterate through columns from 0 to the current row number.

 Step 4: Set edge values (first and last in each row) to 1.

 Step 5: Calculate middle values as the sum of two numbers from the previous row.

 Step 6: Print each value in the current row followed by a space.

 Step 7: Move to a new line after each row is printed.

Submitted Code :