Pascal’s Triangle Printing – Computer Sir Ki Class


Code Learning #CPP#3173 siteicon   siteicon   siteicon  

Pascal’s Triangle Printing

Printing a pascal’s triangle of given number of rows.

Learning Objectives

  • Printing pascal’s triangle of numbers.

Source Code

TC++ #3173

int main()
int r;
cout<<"Enter number of r: ";
int m=1;
for(int i=0;i {
for(int sp = 1; sp <= r-i; sp++)
cout <<" ";
for(int j=0;j<=i;j++)
if (j==0||i==0)m=1;
else m = m*(i-j+1)/j;
cout< }
cout << endl;
return 0;

Source Code


Test it !

Run Output

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

Code Understanding

int r; cout<<“Enter number of r: “; cin>>r;
Collecting number of rows from the user.

int m=1; //The multiplier for calculation of pascal’s number value initialised with 1

for(int i=0;i<r;++i) //Outer loop for row counting

for(int sp = 1; sp <= r-i; sp++)  cout <<” “;  //Loop for space before the first number in a row
for(int j=0;j<=i;j++)  //Inner loop for column in each row
if (j==0||i==0)m=1;     //First row has just 1 to be printed.
else m = m*(i-j+1)/j;    //In other row we calculate pascal’s value by given expression.
cout<<m<< ” “;             //Printing the number followed by some space to make a proper formation
cout << endl;                    //Changing row after each iteration


  • The code given above is optimised for 5 row. For other count some adjustments in initial spaces and inter character spaces may be required for proper visibility of the triangle.
  • There are many special properties of numbers in the pascal’s triangle of numbers. Following link makes an interesting readout.

Suggested Filename(s): pascaltr.cpp


sunmitra| Created: 29-Jan-2018 | Updated: 29-Jan-2018|