{}_n C_r =\binom{n}{r}= \frac{n!}{r!(n-r)!}


\begin{array}{lc}
n=0 &
{\color{Red}\boldsymbol{1}} =\binom{0}{0} \\
\\
n=1  & 
{\color{Red}\boldsymbol{1}}=\binom{1}{0} \quad{\color{Red}\boldsymbol{1}}=\binom{1}{1} \\
\\n=2  & 
{\color{Red}\boldsymbol{1}}=\binom{2}{0}\quad {\color{Red}\boldsymbol{2}}=\binom{2}{1}\quad{\color{Red}\boldsymbol{1}}=\binom{2}{2} \\
\\    n=3  & 
{\color{Red}\boldsymbol{1}}=\binom{3}{0}\quad {\color{Red}\boldsymbol{3}}=\binom{3}{1}\quad{\color{Red}\boldsymbol{3}}=\binom{3}{2}\quad{\color{Red}\boldsymbol{1}}=\binom{3}{3} \\
\\   n=4  & 
{\color{Red}\boldsymbol{1}}=\binom{4}{0}\quad {\color{Red}\boldsymbol{4}}=\binom{4}{1}\quad{\color{Red}\boldsymbol{6}}=\binom{4}{2}\quad {\color{Red}\boldsymbol{4}}=\binom{4}{3}\quad{\color{Red}\boldsymbol{1}}=\binom{4}{4} \\
\\                                           
                                          
\end{array}

#include <iostream>
using namespace std;

//driver code
int main() {
  int rows=5; //no of rows in pascal triangle 
  for(int i=0;i<rows;i++) { //outer loop
    int num=1;
    for(int j=0;j<rows-i-1;j++){ //loop for spaces
      cout<<" ";      
    }
    for(int k=0;k<=i;k++){ //loop for printing numbers
      cout<<num<<" ";
      num=num*(i-k)/(k+1); //formula of pascal triangle
    }
    cout<<endl;
  }
  return 0;
}

What is Pascal's triangle?

OverviewPascal s triangle is a triangular array of binomial coefficients in which each element is the sum of 2 numbers directly above it. This triangular array is made up of summing adjacent elements in preceding rows.Note: It is named after French scientist and mathematician, Blaise Pascal.Pascal s formulaThe formula to calculate the number of ways in which rrr objects can be chosen from nnn objects is given below:

What is Pascal's triangle?

Overview

Pascal's formula

Working

Implementation

Explanation