- Write a program in C to print right triangle star (*) pattern of n rows using for loop.
- Write a C program to print a right angles triangle pattern of star (*) character using loops.
For a exponentially increasing star pattern. Program’s output should be:

Required Knowledge
- For Loop
- printf and scanf function in C
Algorithm to print exponentially increasing star pattern using loop
- Take the number of rows(N) of right triangle as input from user using scanf function.
- Number of stars in Kth row is equal to 2K. 0th row contains 1 star, 1st row contains 2 stars, 3rd row contains 3 stars. In general, Kth row contains 2K stars.
- We will use two for loops to print exponential star pattern.
- For a exponentially increasing star pattern of N rows, outer for loop will iterate N time. Each iteration of outer loop will print one row of the pattern.
- For Kth row of pattern, inner loop will iterate 2k times. Each iteration of inner loop will print one star (*).
Here is the matrix representation of the exponentially increasing star pattern. The row numbers are represented by i whereas column numbers are represented by j.

C program to print exponentially increasing star pattern

#include<stdio.h>
#include<math.h>
int main(){
int i,j,rows;
printf("Enter the number of rows\n");
scanf("%d", &rows);
for(i = 0; i < rows; i++){
/* Prints one row of pattern */
for(j = 0; j < pow(2,i); j++){
printf("*");
}
/* move to next row */
printf("\n");
}
return 0;
}
Output
Enter the number of rows 4 * ** **** ******** ****************