Find the duplicates in a string.

Question: Find the duplicate characters in a string?

Input: floccinaucinihilipilification
Output: a ,c ,f ,i ,l ,n ,o

The idea for this problem would be:-

• Create a character array for the number of characters possible. Take 256 for all the ASCII characters as well.
• Traverse the array and print the characters that have a count greater than 1.

Here is the source code for the same-

#include <stdio.h>

// prints duplicates in str
void findDuplicates(char *str)
{
	
	int count[256] = {0};
	// Scan all characters one by one
    while (*str)
    {
        if (*str == ' ' || *str == '\n' || *str == '\t')
		{
			str++;
			continue;
		}
		
		count[*str]++;
		str++;
    }
 
    int i;
	for(i=0; i<256; i++)
	{
		if(count[i] > 1)
			printf("%c ,",i);
	}
}
 
// Driver program to test above function
int main(void)
{
    char str[] = "floccinaucinihilipilification";

	findDuplicates(str);

	return 0;
}