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C Exercises: Count a total number of duplicate elements in an array

C Array: Exercise-5 with Solution

Write a program in C to count a total number of duplicate elements in an array.

Pictorial Presentation:

C Exercises: Count a total number of duplicate elements in an array

Sample Solution:

C Code:

#include <stdio.h>

void main()
{
    int arr1[100];
	int arr2[100];
	int arr3[100];
    int n,mm=1,ctr=0;
    int i, j;	
	
	
       printf("\n\nCount total number of duplicate elements in an array:\n");
       printf("---------------------------------------------------------\n");	

       printf("Input the number of elements to be stored in the array :");
       scanf("%d",&n);
   
       printf("Input %d elements in the array :\n",n);
       for(i=0;i<n;i++)
        {
	      printf("element - %d : ",i);
	      scanf("%d",&arr1[i]);
	    }
/*----------------- copy in other array ------------------------------------*/
		for(i=0;i<n; i++)
        {
		arr2[i]=arr1[i];
		arr3[i]=0;
        }
/*------------------- mark the elements are duplicate -------------------------*/
	for(i=0;i<n; i++)
        {
		for(j=0;j<n;j++)
			{
				if(arr1[i]==arr2[j])
				{
				arr3[j]=mm;
				mm++;
				}
			}
			mm=1;
        }		
/*--------------- Prints the array ------------------------------------*/
   for(i=0; i<n; i++)
    {
      if(arr3[i]==2){ctr++;}  
    }
      printf("The total number of duplicate elements found in the array is: %d \n", ctr);
    
	  printf("\n\n");		
}

Sample Output:

Count total number of duplicate elements in an array:                                                         
---------------------------------------------------------                                                     
Input the number of elements to be stored in the array :3                                                     
Input 3 elements in the array :                                                                               
element - 0 : 5                                                                                               
element - 1 : 1                                                                                               
element - 2 : 1                                                                                               
                                                                                                              
Total number of duplicate elements found in the array is : 1

Flowchart:

Flowchart: Count total number of duplicate elements in an array

C Programming Code Editor:

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Previous: Write a program in C to copy the elements one array into another array.
Next: Write a program in C to print all unique elements in an array.

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