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program to remove all repeated characters in a string



program to remove all repeated characters in a string

Write a C program to remove all repeated characters in a string using loops. How to remove all duplicate characters from a string using for loop in C programming. Program to find and remove all duplicate characters in a string. Logic to remove all repeated character from string in C program.

Logic to remove repeated characters from string

    Input string from user, store it in some variable say str.
    Run a loop from start to end character of the given string str.
    For each character ch in the string, remove all next occurrences of ch.

#include <stdio.h>
#define maxsize 100 // Maximum string size

/* Function declarations */
void removeDuplicates(char * str);
void removeAll(char * str, const char toRemove, int index);

int main()
{
    char str[maxsize];

    /* Input string from user */
    printf("Enter any string: ");
    gets(str);

    printf("String before removing duplicates: %s\n", str);

    removeDuplicates(str);

    printf("String after removing duplicates: %s\n", str);

    return 0;
}

/* Remove all duplicate characters from the given string */
void removeDuplicates(char * str)
{
    int x = 0;

    while(str[x] != '\0')
    {
        /* Remove all duplicate of character string[x] */
        removeAll(str, str[x], x + 1);
        x++;
    }
}

/* Remove all occurrences of a given character from string. */
void removeAll(char * str, const char toRemove, int index)
{
    int x;

    while(str[index] != '\0')
    {
        /* If duplicate character is found */
        if(str[index] == toRemove)
        {
            /* Shift all characters from current position to one place left */
            x = index;
            while(str[x] != '\0')
            {
                str[x] = str[x + 1];
                x++;
            }
        }

        index++;
    }
}