Question

Q1. Write a C Program to print the duplicate elements of an array.
In this program, you need to print the duplicate elements present in the array.

Answer 1

Certainly! Below is a simple C program that takes an array of integers, checks for duplicate elements, and prints them out.

```c
#include <stdio.h>

int main() {
int arr[100], n, i, j;
int isDuplicate;

// Read the size of the array
printf("Enter the number of elements in the array: ");
scanf("%d", &n);

// Read the elements of the array
printf("Enter the elements:\n");
for(i = 0; i < n; i++) {
scanf("%d", &arr[i]);
}

printf("Duplicate elements in the array are: ");
int foundDuplicate = 0; // Flag to check if any duplicate has been found

// Check for duplicate elements
for(i = 0; i < n; i++) {
isDuplicate = 0; // Reset duplicate flag for new element
for(j = 0; j < i; j++) {
if(arr[i] == arr[j]) {
isDuplicate = 1; // Mark as a duplicate
break;
}
}
if(isDuplicate) {
// Check if we've already printed this duplicate
if (!foundDuplicate) {
printf("%d ", arr[i]);
foundDuplicate = 1; // Set the flag after finding the first duplicate
}
}
}

if (!foundDuplicate) {
printf("No duplicates found.");
}

printf("\n");
return 0;
}
```

### Explanation:
1. **Input Handling**: The program starts by asking the user for the number of elements in the array and then reads the elements.
2. **Duplicate Checking**:
- We use two nested loops to compare each element with the others before it.
- If a duplicate is found, it checks if it has been printed before to avoid printing the same duplicate multiple times.
3. **Output**: Finally, it prints out the duplicate elements or states that none were found.

### How to Compile and Run:
You can copy this code into a C file, say `find_duplicates.c`, then compile and run it using:

```bash
gcc find_duplicates.c -o find_duplicates
./find_duplicates
```

Make sure you have a C compiler like `gcc` installed on your system.