Pattern:
*
***
*****
*******
*********
*******
*****
***
*
Solution
Note: Don't jump directly to the solution, try it out yourself first.
Pattern Breakdown
The pattern has 4 rows, and each row contains stars (*) in a decreasing number:
Upper Half
Row 0: 3 Space 1 star 3 space
Row 1: 2 Space 3 star 2 space
Row 2: 1 Space 5 star 1 space
Row 3: 0 Space 7 star 0 space
Lower Half:
Row 4: 1 Space 5 star 1 space
Row 5: 2 Space 3 star 2 space
Row 6: 3 Space 1 star 3 space
Key observation:
UpperHalf:
The number of spaces decrease with each row, starting from 3 (for row 0) and going down to 0 (for row 3).
The number of star increase with each row, starting from 1 star (for row 0) and going up to 7 star(for row 3).
First Inner Loop (Spaces):
The first inner loop prints the spaces before the number in each row.
The number of spaces in each row is equal to middle_row - row (middle_row= total_row/2)
Second Inner Loop (Stars):
The second inner loop prints the start in each row.
The number of stars in each row increased by 2 for each row.
For the i-th row, the number of stars is 2 * row + 1
Lower Half :
The number of spaces increase with each row, starting from 1 (for row 4) and going down to 3 (for row 6).
The number of star decrease with each row, starting from 5 star (for row 4) and going up to 1 star(for row 6).
First Inner Loop (Spaces):
The first inner loop prints the spaces before the number in each row.
The number of spaces in each row is equal to middle_row - row (middle_row= total_row/2)
Second Inner Loop (Stars):
The second inner loop prints the start in each row.
The number of stars in each row decreased by 2 for each row.
For the i-th row, the number of stars is 2 * row + 1
Video Solution
| Java |
public class Main { public static void main(String[] args) { int total_rows = 7; // Total number of rows in the combined pattern int middle_row = total_rows / 2; // Middle row index (which is 3 for 7 rows)
// Top half (Pyramid) for (int row = 0; row <= middle_row; row++) { // First inner loop for spaces for (int space = 0; space < middle_row - row; space++) { System.out.print(" "); } // Second inner loop for stars for (int star = 0; star < 2 * row + 1; star++) { System.out.print("*"); } System.out.println(); // Move to the next line } // Bottom half (Reverse Pyramid) for (int row = middle_row - 1; row >= 0; row--) { // First inner loop for spaces for (int space = 0; space < middle_row - row; space++) { System.out.print(" "); } // Second inner loop for stars for (int star = 0; star < 2 * row + 1; star++) { System.out.print("*"); } System.out.println(); // Move to the next line } } } |
| C++ |
#include <iostream> using namespace std; int main() { int total_rows = 7; // Total number of rows in the combined pattern int middle_row = total_rows / 2; // Middle row index (which is 3 for 7 rows) // Top half (Pyramid) for (int row = 0; row <= middle_row; row++) { // First inner loop for spaces for (int space = 0; space < middle_row - row; space++) { cout << " "; } // Second inner loop for stars for (int star = 0; star < 2 * row + 1; star++) { cout << "*"; } cout << endl; // Move to the next line } // Bottom half (Reverse Pyramid) for (int row = middle_row - 1; row >= 0; row--) { // First inner loop for spaces for (int space = 0; space < middle_row - row; space++) { cout << " "; } // Second inner loop for stars for (int star = 0; star < 2 * row + 1; star++) { cout << "*"; } cout << endl; // Move to the next line } return 0; } |
| Python |
total_rows = 7 # Total number of rows in the combined pattern middle_row = total_rows // 2 # Middle row index (which is 3 for 7 rows) # Top half (Pyramid) for row in range(middle_row + 1): # First inner loop for spaces for space in range(middle_row - row): print(" ", end="") # Second inner loop for stars for star in range(2 * row + 1): print("*", end="") print() # Move to the next line # Bottom half (Reverse Pyramid) for row in range(middle_row - 1, -1, -1): # First inner loop for spaces for space in range(middle_row - row): print(" ", end="") # Second inner loop for stars for star in range(2 * row + 1): print("*", end="") print() # Move to the next line |
