(using if, if-else, nested if, switch-case)

(using for, while, do-while loops)

C Programs

Share with a Friend

HOME

Print Pascal’s triangle (loop)

Introduction

Pascal’s Triangle is a triangular array of numbers where:

The first and last value in every row is 1.
Every other number is the sum of the two numbers directly above it.

For example, for n = 5, the pattern looks like:

1 1

1 2 1

1 3 3 1

1 4 6 4 1

It is based on binomial coefficients:

C Programs

C Program: Print Pascal’s triangle (loop)

Method 1: Using for loop

#include <stdio.h>
 
long factorial(int n) {
    long f = 1;
    for (int i = 1; i <= n; i++)
        f *= i;
    return f;
}
 
int main() {
    int n, i, j;
    printf("Enter number of rows: ");
    scanf("%d", &n);
 
    for (i = 0; i < n; i++) {
        // Print leading spaces
        for (j = i; j < n - 1; j++)
            printf(" ");
 
        // Print values in the row
        for (j = 0; j <= i; j++)
            printf("%ld ", factorial(i) / (factorial(j) * factorial(i - j)));
 
        printf("\n");
    }
 
    return 0;
}

Output

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

Explanation

Factorial Function computes n!.
Binomial Coefficient Formula → n! / (r! * (n - r)!).
Outer loop → controls number of rows.
Inner loops → print spaces and coefficients.

C Program: Print Pascal’s triangle (loop)

Method 2: Using while loop

#include <stdio.h>
 
long factorial(int n) {
    long f = 1;
    int i = 1;
    while (i <= n) {
        f *= i;
        i++;
    }
    return f;
}
 
int main() {
    int n, i = 0, j;
    printf("Enter number of rows: ");
    scanf("%d", &n);
 
    while (i < n) {
        j = i;
        while (j < n - 1) {
            printf(" ");
            j++;
        }
 
        j = 0;
        while (j <= i) {
            printf("%ld ", factorial(i) / (factorial(j) * factorial(i - j)));
            j++;
        }
 
        printf("\n");
        i++;
    }
 
    return 0;
}

Output

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

Explanation

Factorial Function computes n!.
Binomial Coefficient Formula → n! / (r! * (n - r)!).
Outer loop → controls number of rows.
Inner loops → print spaces and coefficients.

C Program: Print Pascal’s triangle (loop)

Method 3: Using do..while loop

#include <stdio.h>
 
long factorial(int n) {
    long f = 1;
    int i = 1;
    do {
        f *= i;
        i++;
    } while (i <= n);
    return f;
}
 
int main() {
    int n, i = 0, j;
    printf("Enter number of rows: ");
    scanf("%d", &n);
 
    do {
        j = i;
        do {
            if (j < n - 1)
                printf(" ");
            j++;
        } while (j < n);
 
        j = 0;
        do {
            printf("%ld ", factorial(i) / (factorial(j) * factorial(i - j)));
            j++;
        } while (j <= i);
 
        printf("\n");
        i++;
    } while (i < n);
 
    return 0;
}

Output

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

Explanation

Factorial Function computes n!.
Binomial Coefficient Formula → n! / (r! * (n - r)!).
Outer loop → controls number of rows.
Inner loops → print spaces and coefficients.

Basics of C Programming (Introductory Programs)

Control Statements & Loops in C

Functions

Arrays

Strings

Pointers

Structures and Unions

Dynamic Memory Allocation

File Handling

Data Structures in C

Advanced C Programs

User-Defined Number Programs in C

User-Defined String Programs in C

C Programs

Share with a Friend

Loop Programs in C

Print Pascal’s triangle (loop)

Introduction

C Program: Print Pascal’s triangle (loop)

Method 1: Using for loop

Output

Explanation

C Program: Print Pascal’s triangle (loop)

Method 2: Using while loop

Output

Explanation

C Program: Print Pascal’s triangle (loop)

Method 3: Using do..while loop

Output

Explanation