Insert an Element At Beginning of An Array

Insert an element at beginning position in an array of size S.

Algorithm:

1.       START

2.       N = Get Total number of elements currently present in the array (A)

3.       If N==0, goto 5

4.       If (N<S),  move all elements one position right, else goto 7

5.       Ele = Get a new element to insert

6.       A[0] = Ele

7.       STOP

 

Implementation:

Scenario 1: Some elements are present.

Array A[10]. N=5. S=10

ARRAY BEFORE INSERTION:

15

20

26

78

25

 

 

 

 

 

 

1.       START

2.       N=5

3.       N is not zero so goto next step (4).

4.       5<10, which is true, hence move all elements one position right. Array after step#4:

 

15

20

26

78

25

 

 

 

 

 

5.       Ele = 13

6.       A[0] = 13

7.        STOP

 

ARRAY AFTER INSERTION:

13

15

20

26

78

25

 

 

 

 

 

 

 

Scenario 2: Array is empty.

Array A[10]. Size=10

ARRAY BEFORE INSERTION:

 

 

 

 

 

 

 

 

 

 

 

1.       START

2.       N=0

3.       Since N is ZERO, going to 5

4.       <NOT EXECUTED>

5.       Ele = 13

6.       A[0] = 13

7.        STOP

 

ARRAY AFTER INSERTION:

13

 

 

 

 

 

 

 

 

 

 

 

Scenario 3: Array is FULL.

Array A[10]. Size=10

ARRAY BEFORE INSERTION

15

20

26

78

25

27

36

97

12

69

 

1.       START

2.       N=10

3.       N is not ZERO, so going to STEP#4

4.       If(10<10) which is false hence no insertion, going to STEP#7

5.       <NOT EXECUTED>

6.       <NOT EXECUTED>

7.       STOP

 

ARRAY AFTER INSERTION

15

20

26

78

25

27

36

97

12

69

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