🚀 C Program to Remove Duplicates, Ignore Spaces, and Sort Characters in Descending Order

📄 Source Code:

#include<stdio.h>
#include<string.h>

int present(char a[], char ch, int len)
{
    for (int i = 0; i < len; i++)
    {
        if (a[i] == ch)
        {
            return 1;
        }
    }
    return 0;
}

void des(char a[], int len)
{
    for (int i = 0; i < len - 1; i++)
    {
        for (int j = i + 1; j < len; j++)
        {
            if (a[i] < a[j])
            {
                char temp = a[i];
                a[i] = a[j];
                a[j] = temp;
            }
        }
    }
}

int main()
{
    char str[200], result[200];
    int j = 0;
    fgets(str, sizeof(str), stdin);
    int len = strlen(str);
    if (str[len - 1] == '\n')
    {
        str[len - 1] = '\0';
    }

    for (int i = 0; str[i] != '\0'; i++)
    {
        if (str[i] != ' ' && !present(result, str[i], j))
        {
            result[j++] = str[i];
        }
    }

    des(result, j);
    result[j] = '\0';

    printf("Resulting string: %s\n", result);
}
    

📘 Deep Explanation:

This C program performs three core operations on a string entered by the user:

• 🔹 1. It removes duplicate characters from the string.
• 🔹 2. It ignores spaces.
• 🔹 3. It sorts the unique characters in descending order.

• 🔸 present() checks if a character is already in the result array.
• 🔸 des() uses a simple bubble sort in descending (Z to A) order.
• 🔸 fgets() is used instead of scanf() to read spaces.
• 🔸 Only unique characters are printed after sorting.

🧪 Sample Output:

Input:
Hello World

Output:
Resulting string: roledWH