Problem
Write a C program to delete an element from an array at runtime by the user and the result to be displayed on the screen after deletion. If the deleted element is not in an array, then we need to display Invalid Input.
Solution
An array is used to hold the group of common elements under one name.
The array operations are as follows −
- Insert
- Delete
- Search
Algorithm
Refer an algorithm to delete the elements into an array with the help of pointers.
Step 1 − Declare and read the number of elements.
Step 2 − Declare and read the array size at runtime.
Step 3 − Input the array elements.
Step 4 − Declare a pointer variable.
Step 5 − Allocate the memory dynamically at runtime.
Step 6 − Enter an element that to be deleted.
Step 7 − After deletion, the elements are shifted to left by one position.
Example
Size of array is: 5
The array elements are as follows −
1 2 3 4 5
Enter the position the element that to be deleted: 4
The output is as follows −
After deletion the array elements are: 1 2 3 5
Example
Following is the C program to insert the elements into an array with the help of pointers −
#include<stdio.h>
#include<stdlib.h>
void delete(int n,int *a,int pos);
int main(){
int *a,n,i,pos;
printf("enter the size of array:");
scanf("%d",&n);
a=(int*)malloc(sizeof(int)*n);
printf("enter the elements:\n");
for(i=0;i<n;i++){
scanf("%d",(a+i));
}
printf("enter the position of element to be deleted:");
scanf("%d",&pos);
delete(n,a,pos);
return 0;
}
void delete(int n,int *a,int pos){
int i,j;
if(pos<=n){
for(i=pos-1;i<n;i++){
j=i+1;
*(a+i)=*(a+j);
}
printf("after deletion the array elements is:\n");
for(i=0;i<n-1;i++){
printf("%d\n",(*(a+i)));
}
}
else{
printf("Invalid Input");
}
}Output
When the above program is executed, it produces the following output −
enter the size of array:5 enter the elements: 12 34 56 67 78 enter the position of element to be deleted:4 After deletion the array elements are: 12 34 56 78