C PROGRAMMING PROGRAM • PATTERN PROGRAMS

Print a Right-Triangle Star Pattern

Learn how to print a right-triangle star pattern using a clear C program.

IntermediateNested loopsRows and columnsPattern

PROBLEM UNDERSTANDING

Input and expected output

Sample input

Sample output

*
* *
* * *
* * * *

COMPLETE C PROGRAM

Complete C implementation

#include <stdio.h>

int main(void)
{
    int rows;

    printf("Enter number of rows: ");
    scanf("%d", &rows);
    for (int row = 1; row <= rows; row++) {
        for (int column = 1; column <= row; column++) printf("* ");
        printf("\n");
    }
    return 0;
}

CURRENT STEP

Select Start to walk through the important lines.

SELECTED LINE

No line selected

EXPECTED OUTPUT FOR THE SAMPLE

*
* *
* * *
* * * *

0%Step 0 of 0

PROGRAM EXPLANATION

Algorithm and explanation

Read the required input values.
Print exactly row-number stars on each successive line.
Display the computed result.

Print exactly row-number stars on each successive line.

EFFICIENCY

Time and space complexity

Time complexity

O(n²)

Auxiliary space

O(1)

DEBUGGING CHECKLIST

Common mistakes

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Use the correct format specifier for every variable.

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Initialize variables before using their values.

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Check braces, semicolons and input order carefully.

Try it yourself

Practice: Run the program with the sample input, predict its output, and then test one boundary case of your own.