Reverse Right-Angled Triangle Alphabet Pattern in C

What You’ll Learn

Print a reverse alphabet right-angled triangle: each row has one more character than the previous, and letters go from a top letter down toward A — E, ED, EDC, EDCB, EDCBA. Same geometry as Program 1, but descending along the alphabet. Includes a live preview, worked C examples, edge cases, and complexity.

📝 Problem & Approach

Given a row count n (or fixed A–E), print a left-aligned triangle of descending alphabet prefixes.

// Five rows (top = E)
// E
// ED
// EDC
// EDCB
// EDCBA

Inputs & Outputs

Minimal workflow

top = 'A' + rows - 1
for i from top down to 'A':
    for j from top down to i:
        print j
    print newline

Approach comparison

🔮 Live Preview

Choose between 1 and 10 rows and draw the reverse alphabet triangle in the browser.

Press "Draw pattern".

Examples Gallery

Three complete C programs — fixed top E, scanf row count, and spaced letters. . Click View Output to reveal sample console results.

#include <stdio.h>

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

    for (i = 1; i <= 5; ++i) {
        ch = 'E';
        for (j = 1; j <= i; ++j) {
            printf("%c", ch--);
        }
        printf("\n");
    }

    return 0;
}

E
ED
EDC
EDCB
EDCBA

#include <stdio.h>

int main() {
    int rows;
    int i, j;
    char ch;

    printf("Enter the number of rows: ");
    scanf("%d", &rows);

    for (i = 1; i <= rows; ++i) {
        ch = (char)('A' + rows - 1);
        for (j = 1; j <= i; ++j) {
            printf("%c", ch--);
        }
        printf("\n");
    }

    return 0;
}

Enter the number of rows: 4
D
DC
DCB
DCBA

#include <stdio.h>

int main() {
    char top = 'E';
    char i, j;

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

    return 0;
}

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

🔎 Worked Walkthrough — top E

Trace each outer value of i and the letters printed on that row.

Total letters: 1 + 2 + 3 + 4 + 5 = 15 = 5×6/2.

🎯 Practice Problems

Try these variations to lock in the pattern.

Notes

⏱️ Time and Space Complexity

Row k prints k letters; summing 1..n gives n(n+1)/2 character writes.

💡 Best Practices