C program to print natural numbers in right triangle pattern

• Write a C program to print natural numbers right angled triangle.

For a right triangle of 4 rows. Program’s output should be:

Required Knowledge

• For Loop
• printf and scanf function in C

Algorithm to print natural number right triangle pattern using for loop

• Take the number of rows(N) of right triangle as input from user using scanf function.
• Number of integers in K^th row is always K. 1^st row contains 1 integer, 2^nd row contains 2 integers, 3^rd row contains 3 integers and so on. In general, K^th row contains K integers.
• We will use a integer counter to print consecutive natural numbers.
• We will use two for loops to print right triangle of natural numbers.
  • Outer for loop will iterate N time. Each iteration of outer loop will print one row of the pattern.
  • For K^th row of right triangle pattern, inner loop will iterate K times. Each iteration of inner loop will increment the value of counter and print it on screen.

Here is the matrix representation of the natural number triangle pattern. The row numbers are represented by i whereas column numbers are represented by j.

C program to print right triangle star pattern

#include<stdio.h>
 
int main() {
    int i, j, rows, count = 1;
 
    printf("Enter the number of rows\n");
    scanf("%d", &rows);
 
    for (i = 0; i < rows; i++) {
        for (j = 0; j <= i; j++) {
            printf("%d ", count);
            count++;
        }
        printf("\n");
    }
    return(0);
}

Output

Enter the number of rows
4
1
2 3
4 5 6
7 8 9 10