CP PPT_Unit IV computer programming in c.pdf

Computer
Programming in “C”
Unit iV: arraYS in ‘C’

ARRAY in C
• An array is a set of elements of the same data type that are referred
to by the same name.
• An array in C programming language can be defined as “number of
memory locations, each of which can store the same data type and
which can be referred by the same variable name”.
• All arrays consist of continuous memory locations.
• The lowest memory address corresponds to the first element and
the highest address to the last element.

Types of Arrays
Single dimensional Array/ Matrix
Linear Array
Single subscript Two subscripts Multiple subscripts

ARRAYS in C
• Array is a collection of homogenous data stored under unique name.
• The values in an array are called as “Elements of an Array”.
• These elements are accessed by numbers called as “subscripts or
index numbers”.
• Arrays may be of any variable type.
• An Array is declared as
data_type array_name [size]
e.g. int sample[10]

Program for ARRAY
• Output:
The elements of array a
2 3 5 6 7
•

Initializing a Character Array
• Strings are one-
dimensional array of
characters terminated by a
null character ‘0’
• To hold the null character
at the end of an array, the
size of the character array
containing the string is one
more than the number of
characters in the word.
•

Functions
used in
Array
Output:

Single Dimensional Array
• A list of items can be given one variable name using only one subscript.
Such a variable is called as single dimensional array or single
subscripted variable.
• An array which is having either a single row or a single column is
termed as one dimensional array. One dimensional array have the
subscripts in a linear manner.

Program to input 10 numbers from user
and find total of them
• • Output:
Enter any ten numbers: 1
2
3
4
5
6
7
8
9
10
Total is: 55

#include<stdio.h>
int main( )
{
int a[25], n, i ;
float , ;
printf("Enter the number of terms:") ;
scanf("%d", &n) ;
printf("n Enter the Numbers:n") ;
for (i = 0 ; i < n ; i++)
{
scanf("%d", &a[i]) ;
}
12
for (i = 0 ; i < n ; i++)
{
sum = sum + a[i] ;
avg = sum / n ;
}
printf("n Mean of entered
Numbers are : %f ", mean) ;
return ( 0 ) ;
}
Write a Program in c to find the mean of n
numbers using array

• Write a Program in C to find the mean of n numbers using array
13
#include < stdio.h >
int main( )
{
int a[25], n, i ;
float mean = 0, sum = 0 ;
printf(" Enter the Numbers of
terms: ") ;
scanf("%d ",& n) ;
printf("n Enter the Numbers :
n") ;
for ( i = 0 ; i < =n ; i++)
{
scanf("%d ",& a[i]) ;
}
for ( i = 0 ; i < n ; i++)
{
sum = sum + a[i] ;
avg = sum / n ;
}
printf("n Mean of
entered Numbers are :
%f ",mean) ;
return ( 0 ) ;
}

C Program to Copy All the
Elements of One Array to
Another Array
14
#include <stdio.h>
int main()
{
int a[5] = { 3, 6, 9, 2, 5 }, n = 5;
int b[n], i;
printf("The first array is :");
for (i = 0; i < n; i++)
{
printf("%d", a[i]);
}
// copying elements from one array to another
for (i = 0; i < n; i++)
{
b[i] = a[i];
}
// displaying array after copying the
//elements from one array to other
printf("nThe second array is :");
for (i = 0; i < n; i++) {
printf("%d ", b[i]);
}
return 0;
}

Program to find the smallest and largest number from an array.
•

Program to search an element in the array

Program to search an element in the array
• Output:
Enter elements of an array:
10 9 8 7 6 5 4 3 2 1
Enter item to search: 6
Item found at location: 5

18
Reversing Arrays in C
#include<stdio.h>
int main()
{
int i, n, arr[n], i;
printf("Enter the size of the array: ");
scanf("%d", &n);
printf("Enter the elements: ");
for(i = 0; i < n; i++)
{
scanf("%d", &arr[i]);
}
int rev[n], j = 0;
for(j = n-1; j >= 0; j--)
{
rev[j] = arr[i];
}
printf("The Reversed array: ");
for(j = 0; j < n; j++)
{
printf("%d ", rev[j]);
} }

2D Array (Two Dimensional Array)
• The two-dimensional array can be defined as an array of arrays.
• The 2D array is organized as matrices which can be represented as
the collection of rows and columns.
19
Declaration of two dimensional Array in C
The syntax to declare the 2D array is given below.
data_type array_name [rows] [columns];
Consider the following example.
int twodimen[4][3];

• Output:
• Array
contents are:
10 20
30 40
20

Multi Dimensional Array
• C language allows array of 3 or more dimensions is called as multi-
dimensional array.
• The syntax to declare the multi-dimentional array is given below.
• data_type array_name [S1] [S2] [S3] …. [Sn]
• Consider the following example.
• int sample1 [4] [5] [5];
• float sample2 [10] [20] [30];
21

Multi Dimensional Array
•
• Output:
Enter matrix of 3*3:
1 2 3 4 5 6 7 8 9
Matrix is:
1 2 3
4 5 6
7 8 9

C Program to add 2 Matrices
• •

C Program to add 2 Matrices
• Output:
Enter the number of rows and columns of matrix
2 2
Enter the elements of first matrix
1 2
3 4
Enter the elements of second matrix
5 6
2 1
Sum of entered matrices
6 8
5 5

CP PPT_Unit IV computer programming in c.pdf

Sorting:
27
What is Sorting?
A Sorting Algorithm is used to rearrange a given array or list of elements according to a
comparison operator on the elements. The comparison operator is used to decide the
new order of elements in the respective data structure.

Sorting Algorithms:
• Bubble Sort
• Insertion Sort
• Selection Sort
• Merge Sort
• Quick Sort
• Heap Sort
28

Linear Searching :
• Linear search is the simplest method for searching. In Linear search technique of searching;
the element to be found in searching the elements to be found is searched sequentially in
the list.
• This method can be performed on a sorted or an unsorted list
In case of a sorted list searching starts from 0th element and continues until the element is
found from the list or the element whose value is greater than (assuming the list is sorted
in
ascending order), the value being searched is reached.
29

Linear Search Algorithm
• Step 1: First, read the search element (Target element) in the array.
Step 2: In the second step compare the search element with the first
element in the array.
Step 3: If both are matched, display “Target element is found” and
terminate the Linear Search function.
Step 4: If both are not matched, compare the search element with the
next element in the array.
Step 5: In this step, repeat steps 3 and 4 until the search (Target)
element is compared with the last element of the array.
Step 6 :– If the last element in the list does not match, the Linear Search
Function will be terminated, and the message “Element is not found”
will be displayed.
30

Linear Searching C program:
31

Bubble Sort Algorithm
• Bubble Sort is the simplest sorting algorithm that works by repeatedly
swapping the adjacent elements if they are in the wrong order.
32
Input: arr[] = {5, 1, 4, 2, 8}
First Pass:
Bubble sort starts with very first two elements, comparing them to check which one is
greater.
( 5 1 4 2 8 ) –> ( 1 5 4 2 8 ), Here, algorithm compares the first two elements, and swaps
since 5 > 1.
( 1 5 4 2 8 ) –> ( 1 4 5 2 8 ), Swap since 5 > 4
( 1 4 5 2 8 ) –> ( 1 4 2 5 8 ), Swap since 5 > 2
( 1 4 2 5 8 ) –> ( 1 4 2 5 8 ), Now, since these elements are already in order (8 > 5),
algorithm does not swap them.

Bubble Sort Algorithm
33
Second Pass:
Now, during second iteration it should look like this:
( 1 4 2 5 8 ) –> ( 1 4 2 5 8 )
( 1 4 2 5 8 ) –> ( 1 2 4 5 8 ), Swap since 4 > 2
( 1 2 4 5 8 ) –> ( 1 2 4 5 8 )
( 1 2 4 5 8 ) –> ( 1 2 4 5 8 )
Third Pass:
Now, the array is already sorted, but our algorithm does not know if it is completed.
The algorithm needs one whole pass without any swap to know it is sorted.
( 1 2 4 5 8 ) –> ( 1 2 4 5 8 )
( 1 2 4 5 8 ) –> ( 1 2 4 5 8 )
( 1 2 4 5 8 ) –> ( 1 2 4 5 8 )
( 1 2 4 5 8 ) –> ( 1 2 4 5 8 )

Program for sorting an array in ascending order
#include<stdio.h>
int main()
{
int array[50], n, i, j, temp;
printf("Enter the number of elements:n");
scanf("%d",&n);
printf("Enter the %d integers:n",n);
for(i=0;i<n;++i)
{
scanf("%d",&array[i]);
}

Program for sorting an array in ascending order (Continued )
//Ascending Order
for(i=0; i<n; i++)
for(j=i+1; j<n; j++)
{
if(array[i]>array[j])
{
temp=array[i];
array[i]=array[j];
array[j]=temp;
}
}
printf("Sorted list in
ascending order:n");
for(i=0;i<n;i++)
printf("%dn",array[i]);
return 0;
}

36
Arrays in C: Bubble Sort in Ascending order
for(i=0; i<n; i++)
for(j=i+1; j<n; j++)
{
if(a[i]>a[j])
{
temp=a[i];
a[i]=a[j];
a[j]=temp;
}
}
for(i=0; i<n; i++)
{
printf("%dt",a[i]);
}
}
#include<stdio.h>
int main(void)
{
int a[100], i, j, temp, n;
printf("n Enter the max no.of Elements
to Sort: n");
scanf("%d",&n);
printf("n Enter the Elements : n");
for(i=0; i<n; i++)
{
scanf("%d", &a[i]);
}

• Given an array arr[] of N elements, the task is to write a function to
search a given element x in arr[].
• Input: arr[] = {10, 20, 80, 30, 60, 50,110, 100, 130, 170}, x = 110;
Output: 6
Explanation: Element x is present at index 6
• Input: arr[] = {10, 20, 80, 30, 60, 50,110, 100, 130, 170}, x = 175;
Output: -1
Explanation: Element x is not present in arr[].
37

Insertion Sort Algorithm
• Insertion sort algorithm sorts the dataset by transferring
one element at a time to the partially sorted array. Thus,
this sorting algorithm has a low overhead.
38
Consider the following example:
40 30 10 70 50 20 60
We consider 40 as the partially sorted array. When we consider 30, it is less than 40. So we swap
them. Then, we consider 30 and 40 are in the partially sorted array.
30 40 10 70 50 20 60
Now, we consider 10. 10 is less than 30. So, we place the elements as below. 10, 30 and 40 are in
the partially sorted array.
10 30 40 70 50 20 60

39
Now, we consider 70. It is greater than 40, so there is no need for any
movement. 10, 30, 40, 70 are in the partially sorted array.
Now, consider 50. It is less than 70 but greater than 40. We can place them in
the correct position. 10,30, 40, 50,70 are now in the partially sorted array.
10 30 40 50 70 20 60
Now, consider 20. It is greater than 10 but less than 30. We can place it in the
correct position. 10,20,30,40,50, 70 are in the partially sorted array.
10 20 30 40 50 70 60
Consider 60. It is less than 70 but greater than 50. We can place it in the
correct position.
10 20 30 40 50 60 70
Now, we can see that all the elements are sorted. Here, the number of swaps
in insertion sort is minimized but the number of comparisons is still high.

• Before going through the program, lets see the steps
of insertion sort with the help of an example.
Input elements: 89 17 8 12 0
•
Step 1: 89 17 8 12 0 (the bold elements are sorted
list and non-bold unsorted list)
•
Step 2: 17 89 8 12 0 (each element will be
removed from unsorted list and placed at the right
position in the sorted list)
Step 3: 8 17 89 12 0
Step 4: 8 12 17 89 0
Step 5: 0 8 12 17 89 40

41
#include<stdio.h>
int main()
{
int i, j, count, temp, Array[25];
printf("How many numbers u are going
to enter?:");
scanf("%d",&count);
printf("Enter %d elements: ", count);
// This loop would store the input
numbers in array
for(i=0; i<count; i++)
scanf("%d", &Array[i]);
// Implementation of insertion sort algorithm
for(i=1; i<count; i++)
{
temp=Array[i];
j=i-1;
while((temp<Array[j]) && (j>=0))
{
Array[j+1]=Array[j];
j=j-1;
}
Array[j+1]=temp;
}
printf("Order of Sorted elements: ");
for(i=0;i<count;i++)
printf("%d", Array[i]);
return 0;
}
OUTPUT:

• The two-dimensional array can be defined as an array of arrays. The
2D array is organized as matrices which can be represented as the
collection of rows and columns.
42
Declaration of two dimensional Array in C
The syntax to declare the 2D array is given below.
data_type array_name[rows][columns];
Consider the following example.
int twodimen[4][3];

43
C program to Insert an element in an Array
First get the element to be inserted, say x
Then get the position at which this element is to be inserted, say pos
Then shift the array elements from this position to one position forward(towards right),
and do this for all the other elements next to pos.
Insert the element x now at the position pos, as this is now empty.

CP PPT_Unit IV computer programming in c.pdf

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