C program to print a pattern of right triangle using  star

This C program is to print a pattern of right triangle using star(*).

*
* *
* * *
* * * *
* * * * *

Logic

We use a nested for loop which counts till the i^th value and keeps printing a star till that val

Dry Run of the Program

Take input rows=3(where rows= no of rows)

1st iteration outer for loop

for(i=1;i<=row;i++) i.e for(i=1;1<=3;i++)

1st iteration inner for loop

for(j=1;j<=i;j++) i.e for(j=1;1<=1;j++)

printf(“* “) i.e output  *

2nd iteration outer for loop

for(i=1;i<=row;i++) i.e for(i=2;2<=3;i++)

1st iteration inner for loop

for(j=1;j<=i;j++) i.e for(j=1;1<=2;j++)

printf(“* “) i.e output  *

2nd iteration inner for loop

for(j=2;j<=i;j++) i.e for(j=2;2<=2;j++)

printf(“* “) i.e output  * *

3rd iteration outer for loop

for(i=1;i<=row;i++) i.e for(i=3;3<=3;i++)

1st iteration inner for loop

for(j=1;j<=i;j++) i.e for(j=1;1<=3;j++)

printf(“* “) i.e output  *

2nd iteration inner for loop

for(j=2;j<=i;j++) i.e for(j=2;2<=3;j++)

printf(“* “) i.e output  * *

3rd iteration inner for loop

for(j=3;j<=i;j++) i.e for(j=3;3<=3;j++)

printf(“* “) i.e output  * * *

Now, we will break out of the outer for loop as now i=4 which is greater than 3.

Final output will be :-

*

* *

* * *

Program

#include<stdio.h>
void main()
{
    int i,j,rows;

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

Output