C Program to Print Pyramids and Patterns

Half Pyramid of Stars (*)

#include <stdio.h>

int main() {
  int i, j, rows;
  printf("Enter the number of rows : ");
  scanf("%d", &rows);
  for (i = 1; i <= rows; ++i) {
    for (j = 1; j <= i; ++j) {
      printf("* ");
    }
    printf("\n");
  }
  return 0;
}

Output

Enter the number of rows : 6
* 
* * 
* * * 
* * * * 
* * * * * 
* * * * * *

---

Half Pyramid of Numbers

#include <stdio.h>

int main() {
  int i, j, rows;
  printf("Enter the number of rows: ");
  scanf("%d", &rows);
  for (i = 1; i <= rows; ++i) {
    for (j = 1; j <= i; ++j) {
      printf("%d ", j);
    }
    printf("\n");
  }
  return 0;
}

Output

Enter the number of rows: 6
1 
1 2 
1 2 3 
1 2 3 4 
1 2 3 4 5 
1 2 3 4 5 6 

---

Half Pyramid of Alphabets

#include <stdio.h>
#include <stdio.h>

int main() {
  int i, j;
  char input, alphabet = 'A';
  printf("Enter a character to print at last : ");
  scanf("%c", &input);
  input = toupper(input);
  for (i = 1; i <= (input - 'A' + 1); ++i) {
    for (j = 1; j <= i; ++j) {
      printf("%c ", alphabet);
    }
    ++alphabet;
    printf("\n");
  }
  return 0;
}

Output

Enter a character to print at last : f
A 
B B 
C C C 
D D D D 
E E E E E 
F F F F F F 

---

Inverted half pyramid of Stars (*)

#include <stdio.h>

int main() {
  int i, j, rows;
  printf("Enter the number of rows: ");
  scanf("%d", &rows);
  for (i = rows; i >= 1; i--) {
    for (j = 1; j <= i; j++) {
      printf("* ");
    }
    printf("\n");
  }
  return 0;
}

Output

Enter the number of rows: 6
* * * * * * 
* * * * * 
* * * * 
* * * 
* * 
* 

---

Inverted half pyramid of numbers

#include <stdio.h>

int main() {
  int i, j, rows;
  printf("Enter the number of rows : ");
  scanf("%d", &rows);
  for (i = rows; i >= 1; i--) {
    for (j = 1; j <= i; j++) {
      printf("%d ", j);
    }
    printf("\n");
  }
  return 0;
}

Output

Enter the number of rows : 6
1 2 3 4 5 6 
1 2 3 4 5 
1 2 3 4 
1 2 3 
1 2 
1 

---

Full Pyramid of Star(*)

#include <stdio.h>

int main() {
  int i, space, rows = 0, j = 0;
  printf("Enter the number of rows: ");
  scanf("%d", &rows);
  for (i = 1; i <= rows; ++i, j = 0) {
    for (space = 1; space <= rows - i; ++space) {
      printf("  ");
    }
  while (j != 2 * i - 1) {
    printf("* ");
    ++j;
  }
  printf("\n");
  }
  return 0;
}

Output

Enter the number of rows: 6
          * 
        * * * 
      * * * * * 
    * * * * * * * 
  * * * * * * * * * 
* * * * * * * * * * * 

---

Full Pyramid of Numbers

#include <stdio.h>

int main() {
  int i, space, rows, j = 0, count = 0, count1 = 0;
  printf("Enter the number of rows: ");
  scanf("%d", &rows);
  for (i = 1; i <= rows; ++i) {
    for (space = 1; space <= rows - i; ++space) {
      printf("  ");
      ++count;
    }
    while (j != 2 * i - 1) {
      if (count <= rows - 1) {
        printf("%d ", i + j);
        ++count;
      } else {
        ++count1;
        printf("%d ", (i + j - 2 * count1));
      }
      ++j;
    }
    count1 = count = j = 0;
    printf("\n");
  }
  return 0;
}

Output

Enter the number of rows: 5
        1 
      2 3 2 
    3 4 5 4 3 
  4 5 6 7 6 5 4 
5 6 7 8 9 8 7 6 5 

---

Inverted full pyramid of Stars(*)

#include <stdio.h>

int main() {
  int i, j, rows, space;
  printf("Enter the number of rows : ");
  scanf("%d", &rows);
  for (i = rows; i >= 1; i--) {
    for (space = 0; space < rows - i; ++space)
      printf("  ");
    for (j = i; j <= 2 * i - 1; j++)
      printf("* ");
    for (j = 0; j < i - 1; j++)
      printf("* ");
      printf("\n");
  }
  return 0;
}
                    

Output

Enter the number of rows : 6
* * * * * * * * * * * 
  * * * * * * * * * 
    * * * * * * * 
      * * * * * 
        * * * 
          * 

---

Pascal's Triangle

What is a Pascal Triangle?

Pascal’s Triangle is a kind of number pattern. The numbers are so arranged that they reflect as a triangle.

To build the triangle, start with "1" at the top, then continue placing numbers below it in a triangular pattern. Each number is the numbers directly above it added together.

#include <stdio.h>

int main() {
  int  i, j, rows, k = 1, space;
  printf("Enter the number of rows: ");
  scanf("%d", &rows);
  for (i = 0; i < rows; i++) {
    for (space = 1; space <= rows - i; space++)
      printf("  ");
    for (j = 0; j <= i; j++) {
      if (j == 0 || i == 0)
        k = 1;
      else
        k = k * (i - j + 1) / j;
      printf("%4d", k);
    }
    printf("\n");
  }
  return 0;
}

Output

Enter the number of rows: 6
          1
        1   1
      1   2   1
    1   3   3   1
  1   4   6   4   1
1   5  10  10   5   1

---

Floyd's Triangle

What is a Floyd's Triangle?

Floyd's triangle is a right angled triangle, which is made using natural numbers. It starts from 1 and consecutively selects the next greater number in sequence.

#include <stdio.h>

int main() {
  int rows, i, j, num = 1;
  printf("Enter the number of rows: ");
  scanf("%d", &rows);
  for (i = 1; i <= rows; i++) {
    for (j = 1; j <= i; ++j) {
      printf("%d ", num);
      ++num;
    }
    printf("\n");
  }
  return 0;
}

Output

Enter the number of rows: 6
1 
2 3 
4 5 6 
7 8 9 10 
11 12 13 14 15 
16 17 18 19 20 21