Add Delete Array Elements 1

#include <stdio.h>
void add(int [],int *, int, int);
void display(int [],int);
void delete(int [],int *, int, int);
int main()
{
    int arr[20], n, i, x, in;
    printf("Enter the total number of elements: ");
    scanf("%d", &n);
    printf("Enter the %d elements: ", n);
    for(i=0; i<n; i++)
        scanf("%d ", &arr[i]);
    printf("Enter the number to be added and the position: ");
    scanf("%d %d", &x, & in);
    add(arr, &n, x, in);
    display(arr, n);
    delete(arr, &n, x, in);
    display(arr, n);
    
    return 0;
}

void add(int a[],int *p, int x, int in)
{
    int n=*p, temp, t;
    for(int i=0; i<=n; i++)
    {
        if(i=in)
        {
            temp=a[i];
            a[i]=x;
        }
        if(i>in)
        {
            t= a[i];
            a[i]=temp;
            temp=t;
        }
        
    }
}

void delete(int a[],int *p, int x, int in)
{
    int n=*p;
    for(int i=0; i<=n; i++)
    {
        if(i>in)
        {
            a[i]=a[i+1];
        }
        
    }
}

void display(int a[],int n)
{
    for(int i=0; i<n; i++)
        printf("%d  ", a[i]);
}