C program to print palindrome triangle pattern

  • Write a C program to print palindrome triangle pattern of n rows.

Palindrome triangle pattern of 5 rows:
Palindrome_Triangle_Pattern

Required Knowledge

  • For Loop
  • If Else Statement
  • printf and scanf function in C

Algorithm to print triangle pattern of palindrome strings

This program is silimar to right triangle star pattern program.

  • Take the number of rows(N) of right triangle as input from user using scanf function.
  • Number of characters in Kth row is always 2K+1. 0th row contains 1 character, 1st row contains 3 characters, 2nd row contains 5 charcaters and so on.
  • In any row, we will first print the characters in increasing order of their ASCII value till mid of the row and then in decreasing order.
  • We will use two for loops to print right triangle of palindrome strings.
    • Outer for loop will iterate N time(from i = 0 to 2N-2 in increment of 2). Each iteration of outer loop will print one row of the pattern.
    • Each iteration of inner loop will print a palindrome string as explained above.

Here is the matrix representation of the above mentioned pattern. The row numbers are represented by i whereas column numbers are represented by j.
Palindrome_Triangle_Pattern

C program to print palindrome triangle pattern

C program to print palindrome triangle pattern

#include<stdio.h>
 
int main() {
    int i, j, rows, count=0;
 
    printf("Enter the number of rows\n");
    scanf("%d", &rows);
 
    for (i = 0; i < 2*rows; i=i+2) {
        for (j = 0; j <= i; j++) {
            printf("%c", 'A'+count);
            if(j < i/2)
                count++;
            else
                count--;
        }
        count = 0;
        printf("\n");
    }
    return(0);
}

Output

Enter the number of rows
5
A
ABA
ABCBA
ABCDCBA
ABCDEDCBA