Write a C Program to delete the duplicate numbers in an array

Let the user enter the numbers in an array, which contains duplicate elements.

Now, let’s write a code to delete the repeated numbers or elements in an array and make an array with unique elements without duplicates

For example,

An example is explained below −

• User input is 12, 30, 12, 45, 67, 30.
• Output is 12, 30, 45, 67 (after deleting duplicates).

Program

Following is the C program to delete the duplicate numbers in an array −

 Live Demo

#include <stdio.h> #define MAX 100 // Maximum size of the array int main(){    int array[MAX]; // Declares an array of size 100    int size;    int i, j, k; // Loop variables    /* Input size of the array */    printf("enter the size of array : ");    scanf("%d", &size);    /* Input elements in the array */    printf("Enter elements in an array : ");    for(i=0; i<size; i++){       scanf("%d", &array[i]);    }    /*find the duplicate elements in an array:    for(i=0; i<size; i++){       for(j=i+1; j<size; j++){          /* If any duplicate found */          if(array[i] == array[j]){             /* Delete the current duplicate element */             for(k=j; k<size; k++){                array[k] = array[k + 1];             }             /* Decrement size after removing duplicate element */             size--;             /* If shifting of elements occur then don't increment j */             j--;          }       }    }    printf("
Array elements after deleting duplicates : ");/*print an array after deleting the duplicate elements.    for(i=0; i<size; i++){       printf("%d\t", array[i]);    }    return 0; }

Output

The output is as follows −

enter the size of array : 10 Enter elements in an array : 23 12 34 56 23 12 56 78 45 56 Array elements after deleting duplicates : 23 12 34 56 78 45