Operations

Insertion Operation

Inserting one or more element into an array is refers as Insertion Operation. According to the specification, a new element can be insert in following ways.

• Insertion at the beginning of an array

• Insertion at the given index of an array

• Insertion after the given index of an array

• Insertion before the given index of an array

Algorithm: (Inserting into a Linear Array) INSERT (LA, N, K, ITEM) Here LA is a linear array with N elements and K is a positive integer such that K≤N. This algorithm inserts an elements ITEM into the Kth position in LA.

[Initialize counter.] Set J: = N.

Repeat Steps 3 and 4 while J≥K.

[Move Jth element downwards]. Set LA[J + 1]:= LA[J]

[Decrease counter.] Set J:= J-1.

[End of Step 2 loop]

[Insert element.] Set LA[K] :=ITEM.

[Reset N.] Set N:= N+1.

Exit.

Deletion Operation

Removing an element from the array and rearranging the array‘s all elements known as Deletion in the array. Following algorithm deletes the Kth element from a linear array LA and assigns it to a variable ITEM.

Algorithm: (Deleting from a Linear Array) DELETE(LA, N, K, ITEM)

Here LA is a linear array with N elements and K is a positive integer such that K≤N. This algorithm deletes the Kth element from LA.

Set ITEM:= LA[K]

Repeat for J =K to N-1:

[Move J + 1st element upward] Set LA[J]:=LA[J+1].

[End of loop]

[Reset the number of N elements in LA] Set N:=N-1.

Exit.

Search Operation

Searching an element in the array can be based on its value or its index. Consider LA is a linear array with N elements and K is a positive integer such that K≤N. Following is the algorithm to find an element with a value of ITEM using sequential search.

Algorithm: (Searching into a Linear Array) SEARCH (LA, N, K, ITEM)

[Initialize counter.] Set J: = 0.

Repeat Steps 4 and 5 while J < N.

If LA[J]:= ITEM then GOTO STEP 6

Set J = J +1

PRINT J, ITEM

Exit.

Update Operation

Update operation can be performed according to a specified index of an existing element from the array. Consider LA is a linear array with N elements and K is a positive integer such that K≤N. Following is the algorithm to update an element available at the Kth position of LA.

Algorithm: (Updating into a Linear Array) UPDATE (LA, N, K, ITEM)

Initialize Counter.

Set LA[K-1] = ITEM

Exit.

Listing: Following program is showing the implementation of array and performing all the operations on array.

/* Program to perform array operations */

#include<stdio.h>

#define MAX 5

void insert(int*, int pos, int num);

void del(int*, int pos);

void reverse(int*);

void display(int* );

void search(int*, int num);

void main( )

{

int myarray[5];

insert(myarray, 1, 11);

insert(myarray, 2, 12);

insert(myarray, 3, 13);

insert(myarray, 4, 14);

insert(myarray, 5, 15);

printf(“\n Elements of Array: ”);

display(myarray);

del(myarray, 5);

del(myarray, 2);

printf(“\n\n After deletion: ”);

display(myarray);

insert(myarray, 2, 222) ;

insert(myarray, 5, 555) ;

printf(“\n\n After insertion of the elements:”);

display(myarray);

reverse(myarray);

printf(“\n\n After reversing the element: ”);

display(myarray);

search(myarray, 222);

search(myarray, 666);

getch();

}

/* Insert an element num at given position pos */

void insert(int *myarray, int pos, int num)

{

// shift elements to the right

int i;

for(I = MAX-1 ; I >=pos ; i--)

myarray[i] = myarray[i-1];

myarray[i] = num;

}

// Delete an element from the given position pos

void del(int*myarray, int pos)

{

//skip to the desired position

int i;

For(i = pos; i < MAX ; i++)

myarray[i-1] = myarray[i];

myarray[i-1] = 0;

}

// Reverse the entire array

void reverse(int* myarray)

{

int i;

for (i =0; i< MAX/2; i++)

{

int temp = myarray[i];

myarray[i] = myarray[MAX-1-i];

myarray[MAX-1-i] = temp;

}

}

// searches array for a given element num

void search(int*myarray, int num)

{

// traverse the array

int i;

for (i = 0; i< MAX; i++)

{

if(myarray[i] == num)

{

printf(“\n\n The element %d is present at %dth position., num, i + 1”);

return 0;

}

}

if(i== MAX)

printf(“\n\n The element %d is not present in the array.”, num );

}

//Display the contents of array

void display(int*myarray)

{

//traverse the entire array

int i;

printf(“\n”);

for(i=0; i<MAX ; i++)

printf(“%d\t”, myarray[i]);

}