Right-Aligned Alphabet Pyramid in C

What You’ll Learn

Right-align the pyramid by printing a shrinking number of leading spaces, then printing letters from A up to the current row letter (restarting each row). Because we print letters using %2c, use a monospace font if you want the right edge to look perfect. Compare Program 22 (right-aligned sequential stream) and Program 16 (centered). Includes a live preview, worked C examples, edge cases, and complexity.

📝 Problem & Approach

Given a top letter (or fixed E), print a right-aligned pyramid of alphabet prefixes ending at that letter.

// Five rows (monospace; leading spaces + width-2 letters)
//     A
//    A B
//   A B C
//  A B C D
// A B C D E

Inputs & Outputs

Minimal workflow

for i from 'A' to top:
    for j from top down while j > i:
        print one space
    for k from 'A' to i:
        print k with width 2
    print newline

Approach comparison

🔮 Live Preview

Choose a top letter from A to F and draw the right-aligned alphabet pyramid in the browser (monospace).

Press "Draw pattern".

Examples Gallery

Three complete C programs — fixed A–E, scanf top letter, and an int-index style. Click View Output to reveal sample console results.

#include <stdio.h>

int main() {
    char i, j, k;

    for (i = 'A'; i <= 'E'; ++i) {
        for (j = 'E'; j > i; --j) {
            printf(" ");
        }
        for (k = 'A'; k <= i; ++k) {
            printf("%2c", k);
        }
        printf("\n");
    }

    return 0;
}

    A
   A B
  A B C
 A B C D
A B C D E

#include <stdio.h>

int main() {
    char top, i, j, k;

    printf("Enter top letter (like E): ");
    scanf(" %c", &top);

    for (i = 'A'; i <= top; ++i) {
        for (j = top; j > i; --j) {
            printf(" ");
        }
        for (k = 'A'; k <= i; ++k) {
            printf("%2c", k);
        }
        printf("\n");
    }

    return 0;
}

Enter top letter (like E): C
  A
 A B
A B C

#include <stdio.h>

int main() {
    char top = 'E';
    int n = top - 'A' + 1;
    int row, s, L;

    for (row = 1; row <= n; ++row) {
        for (s = 0; s < n - row; ++s) {
            printf(" ");
        }
        for (L = 0; L < row; ++L) {
            printf("%2c", (char)('A' + L));
        }
        printf("\n");
    }

    return 0;
}

    A
   A B
  A B C
 A B C D
A B C D E

🔎 Worked Walkthrough — Top = E

Trace each row’s pad count, letter prefix, and printed line.

Pad count = top - i. Letters always restart at A.

🎯 Practice Problems

Try these variations to lock in the pattern.

Notes

⏱️ Time and Space Complexity

Each of n rows does O(n) pad + letter work, so total work is O(n²).

💡 Best Practices