# C Program to Print Pascal Triangle till N Rows

• Write a C program to print pascal triangle till N rows by calculating binomial coefficients.
• Algorithm to print pascal triangle.

<h4″>Required Knowledge

Pascal Triangle is a regular triangle of binomial coefficients. The counting of rows of the pascal triangle starts with 0 from top to bottom and elements in any particular row are numbered from left to right starting from 0.

Here is the formulae to find the value of nth element of rth row of pascal triangle.

### C program to print pascal triangle till N rows

#include <stdio.h>

int getFactorial(int n);

int main() {
int row, rows, i, value;

printf("Enter Number of Rows of Pascal Triangle\n");
scanf("%d", &rows);

for(row = 0; row < rows; row++) {
/* Print Spaces for every row */
for(i = row; i <= rows; i++)
printf("  ");

for(i = 0; i <= row; i++) {
value = getFactorial(row)/(getFactorial(i)*getFactorial(row-i));
printf("%4d", value);
}

printf("\n");
}

return 0;
}

/*
* Function to calculate factorial of a number
*/
int getFactorial(int N){
if(N < 0){
printf("Invalid Input: factorial not defined for \
negative numbers\n");
return 0;
}
int nFactorial = 1, counter;
/*  N! = N*(N-1)*(N-2)*(N-3)*.....*3*2*1  */
for(counter = 1; counter <= N; counter++){
nFactorial = nFactorial * counter;
}
return nFactorial;
}

Output

Enter Number of Rows of Pascal Triangle
5
1
1 1
1 2 1
1 3 3 1
1 4 6 4 1