Right-Aligned Sequential Pyramid in C

What You’ll Learn

Print letters in a running sequence (A, then B C, then D E F…) while keeping the triangle right-aligned by printing empty 2-column cells first. View output in a monospace terminal because alignment relies on fixed-width cells. Compare Program 13 (sequential, left-aligned) and Program 20 (right-aligned reverse). Includes a live preview, worked C examples, edge cases, and complexity.

📝 Problem & Approach

Given a row count n (or fixed 5), print a right-aligned pyramid of continuous alphabet letters in 2-column cells.

// Five rows (monospace; each cell is width 2)
//         A
//       B C
//     D E F
//   G H I J
// K L M N O

Inputs & Outputs

Minimal workflow

k = 'A'
for i in 1..n:
    for j from n down to 1:
        if j > i: print two spaces
        else: print k with width 2; k++
    print newline

Approach comparison

🔮 Live Preview

Choose between 1 and 6 rows and draw the right-aligned sequential pyramid in the browser (monospace cells).

Press "Draw pattern".

Examples Gallery

Three complete C programs — fixed 5 rows, scanf row count, and explicit pad + letter loops. Click View Output to reveal sample console results.

#include <stdio.h>

int main() {
    int i, j;
    char k = 'A';

    for (i = 1; i <= 5; ++i) {
        for (j = 5; j >= 1; --j) {
            if (j > i) {
                printf("  ");
            } else {
                printf("%2c", k++);
            }
        }
        printf("\n");
    }

    return 0;
}

        A
      B C
    D E F
  G H I J
K L M N O

#include <stdio.h>

int main() {
    int n, i, j;
    char k = 'A';

    printf("Enter number of rows (like 5): ");
    scanf("%d", &n);

    for (i = 1; i <= n; ++i) {
        for (j = n; j >= 1; --j) {
            if (j > i) {
                printf("  ");
            } else {
                printf("%2c", k++);
            }
        }
        printf("\n");
    }

    return 0;
}

Enter number of rows (like 5): 3
    A
  B C
D E F

#include <stdio.h>

int main() {
    int n = 5;
    char k = 'A';
    int i, s, L;

    for (i = 1; i <= n; ++i) {
        for (s = 0; s < n - i; ++s) {
            printf("  ");
        }
        for (L = 0; L < i; ++L) {
            printf("%2c", k++);
        }
        printf("\n");
    }

    return 0;
}

        A
      B C
    D E F
  G H I J
K L M N O

🔎 Worked Walkthrough — 5 rows

Trace each row’s pads, letters, and the running counter range.

Total letters: 1+2+3+4+5 = 15 (A through O). Each cell is 2 columns wide.

🎯 Practice Problems

Try these variations to lock in the pattern.

Notes

⏱️ Time and Space Complexity

Each of n rows scans n cells (or pads + letters totaling n), so total work is O(n²).

💡 Best Practices