Array notes

Deepika, Asst. Professor, Dept. of CS and E, PESCE, Mandya
1
Unit-4
Arrays
Why we have to go for arrays:
To store 100 integer items, we want 100 integer variables to store, i.e int a1, a2, a3,
…………….., a100;
To store 1000 integer items, we want 1000 integer variables to store, i.e int a1, a2,
a3,…………………, a1000;
Using arrays int a[10]; //10 integer items
int a[1000]; // 1000 integer items
int a[100000]; // 100000 integer items
What is Array?
Array is a collection of similar kind of data items.
i.e int a[10]; // a is an array, we can store 10 integer items
i.e float b[10]; // b is an array, we can store 10 floating items
Note: In array we can store only similar kind of data items, but we can’t store dissimilar kind
of data items.
Arrays has been classified into two types, they are
1) One dimensional array(1D)
2) Two dimensional array(2D)
One dimensional array(1D) – one dimensional array(1D) is a linear list which stores array
elements continuous one after the other in the memory.
How to declare 1D array
datatype array_name[size];
int a[10]; // a is an array which stores 10 integer data items
float b[100]; //b is an array which stores 100 floating data items
long int c[10]; // c is an array which stores 10 long integer items
How to find the size of an array
size of an array is calculated as = size * type of data storing in array
int a[4];
size of this array is = 4*2 i.e size of an array is 4 and type of data storing in array is int

2
int a[4];
2 bytes 2bytes 2 bytes 2 bytes
a[0] a[1] a[2] a[3]
this array size is 4*2=8
float b[5];
4 bytes 4 bytes 4 bytes 4bytes 4 bytes
b[0] b[1] b[2] b[3] b[4]
so, this array size is = 5*4= 20 bytes
char d[6]={‘a’,’b’,’c’,’d’,’e’};
1 byte 1 byte 1 byte 1byte 1byte 1byte
b[0] b[1] b[2] b[3] b[4] b[5]
so, this array size is = 6*1= 6 bytes
How to initialize 1D array
datatype array_name[size] = {v1,v2,v3,………………….,vn};
i.e v1,v2,v3,…………..,vn are the values stored in the array
Example:
int a[5]={10,20,30,40,50};
10 20 30 40 50
a[0] a[1] a[2] a[3] a[4]
float b[4]={2.0, 3.4, 1.6, 7.8};
2.0 3.4 1.6 7.8
a[0] a[1] a[2] a[3]
char d[5]={‘B’,’E’,’F’,’G’,’H’};
B E F G H
a[0] a[1] a[2] a[3] a[4]
Different ways of initializing 1D array
1) Initializing all specified memory locations
2) Partial array initialization
3) Array initialization without size
4) String initialization

3
Initialization all specified memory locations
In this array, all the memory locations are filled with values.
int a[5]={10,20,30,40,50}; //array a with five elements and the elements are 10,20,30,40,50
are stored in all the five memory locations
10 20 30 40 50
a[0] a[1] a[2] a[3] a[4]
float b[4]={3.1, 2.6, 7.9, 4.5}; //array a with 4 elements and the elements are 3.1, 2.6, 7.9,
4.5 are stored in all the four memory locations
Partial array initialization
In this array, partial filling of elements in an array.
int a[5]={10,20}; //in this array a, we can store five
elements but here we are storing two elements and the remaining spaces are filled with
zero’s. In this array we can store maximum five elements.
10 20 0 0 0
a[0] a[1] a[2] a[3] a[4]
Array initialization without size
We can declare an array without size
Example1 :
int a[ ]={10,20,30}; //in this array a, size is not specified that time it will see the number of
elements(i.e number of elements are 3 and data to be stored in an array will be int
so, size will be 3*2=6 bytes. So the data stores in the memory as shown below
10 20 30
a[0] a[1] a[2]
Example2:
float b[ ]={3.1, 2.6, 7.9, 4.5}; // in this array b, size is not specified that time it will see the
number of elements(i.e number of elements are 4 and data to be stored in an array will be of
float.
so, size will be 4*4=6 bytes. So the data stores in the memory as shown below
3.1 2.6 7.9 4.5
b[0] b[1] b[2] b[3]

4
so, array b with 4 elements and the elements are 3.1, 2.6, 7.9, 4.5 are stored in all the four
memory locations
String initialization
Initialize the array with a string(i.e array of characters is called string)
char e[10]=”computer”; //here string computer stores in the string variable e
C o M P u t E r 0 0
e[0] e[1] e[2] e[3] e[4] e[5] e[6] e[7] e[8] e[9]
char d[10]=”abc def”;
d[0] d[1] d[2] d[3] d[4] d[5] d[6] d[7] d[8] d[9]
How To Read An Array Elements
int a[5]; //declare an array a with five elements of type ineteger….but how to read an array
elements from the user or keyboard
int a[5];
a[0] a[1] a[2] a[3] a[4]
note: once we declare an array, memory will be allocated how to read array elements
int a[5];
int i;
for(i=0;i<5;i++)
{
scanf(“%d”,&a[i]);
}
Note: array initialization starts from zero position in the memory.
How to display array elements
int a[5]={10,20,30,40,50};
int i;
for(i=0;i<5;i++)
{
A b C d e F 0 0 0

5
printf(“%d “,a[i]);
}
Output:
10 20 30 40 50
How to read and display array of five integer elements
#include<stdio.h>
void main()
{
int a[5];
int i;
printf(“read array of five integer numbers”);
for(i=0;i<5;i++)
{
}
printf(“display array elements”);
for(i=0;i<5;i++)
{
}
1) Write a program to read and display array of 10 floating point numbers
#include<stdio.h>
void main( )
{
float a[10];
int i;
printf(“read array of 10 floating point numbers”);
for(i=0;i<10;i++)
Input:
Read array of five integer numbers
10 20 30 40 50
Output:
Display array elements
10 20 30 40 50

6
{
scanf(“%f”,&a[i]);
}
for(i=0;i<10;i++)
{
printf(“%f “,a[i]);
}
}
Input :
read array of 10 floating point numbers
2.3 4.5 6.7 3.4 2.8 4.1 5.56 4.89 5.66 3.34
Output:
display array elements are
2.3 4.5 6.7 3.4 2.8 4.1 5.56 4.89 5.66 3.34
2) Write a program to read and display array of 8 very long integer numbers.
#include<stdio.h>
void main( )
{
long int a[8];
int i;
printf(“read array of 8 very long integer numbers”);
for(i=0;i<8;i++)
{
scanf(“%ld”,&a[i]);
}
for(i=0;i<8;i++)

7
{
Printf(“%ld”,a[i]);
}
Output:
read array of 8 very long integer numbers
222 45345 56756 666678 789999 34567834 555674567 786786567
display array elements
222 45345 56756 666678 789999 34567834 555674567 786786567
3) Write a program to read and display an array of ‘N’ integer numbers
#include<stdio.h>
void main( )
{
int a[100];
int i,n;
printf(“enter size of an array”);
scanf(“%d”,&n);
printf(“enter array elements”);
for(i=0;i<n;i++)
{
}
for(i=0;i<n;i++)
{
printf(“%d”,a[i]);
}
}
Output:

8
enter size of array
4
Enter array elements
10 20 30 40
display array elements
10 20 30 40
4) Write a C program to find the sum of an array of 5 integer numbers.
#include<stdio.h>
void main( )
{
int a[5];
int i,sum;
printf(“enter all five integer elements”);
for(i=0;i<5;i++)
{
}
sum=0;
for(i=0;i<5;i++)
{
sum=sum+i;
}
printf(“sum=%d”,sum);
}
Output:
Enter all five integer elements
1 2 3 4 5
Sum=15

9
5) Write a C program to find the sum of an array of N integer numbers.
#include<stdio.h>
void main( )
{
int a[100];
int i,n, sum;
printf(“enter the size of an array”);
scanf(“%d”,&n);
printf(“enter all integer elements”);
for(i=0;i<n;i++)
{
}
sum=0;
for(i=0;i<n;i++)
{
sum=sum+i;
}
}
Input:
enter the size of an array
4
enter all integer elements
1 2 3 4
Sum=10

10
6) Write a C program to find the first largest element in array of N integer numbers.
#include<stdio.h>
Void main()
{
inta[100],big;
int i,n;
scanf(“%d”,&n);
printf(“read array elements”);
for(i=0;i<n;i++)
{
}
big=a[0];
for(i=0;i<n;i++)
{
If(a[i]>big)
{
big=a[i];
}
}
printf(“biggest element is=%d”,big);
}
Input:
enter the size of an array
4
read array elements
1 2 5 3
Output:

11
biggest element is = 5
7) Write a C program to find the sum of even numbers and the sum of odd numbers
from an array of N integer numbers.
#include<stdio.h>
void main( )
{
int a[100];
int i,n, esum,osum;
scanf(“%d”,&n);
printf(“enter all integer elements”);
for(i=0;i<n;i++)
{
}
esum=0;
osum=0;
for(i=0;i<n;i++)
{
if(a[i]%2==0)
esum=esum+a[i];
else
osum=osum+a[i];
}
printf(“esum=%d”,esum);
printf(“osum=%d”,osum);
}

12
8) Write a C program to read array A with 10 elements and array B with 10 elements
and find C array, such that C will be given below,
C[0]=A[0]+B[9];
C[1]=A[1]+B[8];
---------------------
---------------------
C[9]=A[9]+B[0];
#include<stdio.h>
void main( )
{
int A[10],B[10],C[10];
int i;
printf(“enter array A elements”);
for(i=0;i<10;i++)
{
scanf(“%d”,&A[i]);
}
printf(“enter array B elements”);
for(i=0;i<10;i++)
{
scanf(“%d”,&B[i]);
}
for(i=0;i<10;i++)
{
C[i]=C[i-1]+C[i-2];
}
printf(“C array will be ………………..”);
for(i=0;i<10;i++)
{
printf(“%d “,C[i]);
}

13
}
9) Write a C program to print ‘N’ Fibonacci numbers using arrays.
Note : Fibonacci numbers are 0,1,1,2,3,5,8,13,………………….,N
#include<stdio.h>
Void main()
{
int a[100];
int i,n;
printf(“enter the n value”);
scanf(“%d”,&n);
a[0]=0; //first Fibonacci numbers
a[1]=1; // second Fibonacci numbers
for(i=2;i<n;i++)
{
a[i]= a[i-1]+a[i-2];
}
printf(“Fibonacci numbers are………..”);
for(i=0;i<n;i++)
{
}
}
10. Write a C program to find the mean, varience and deviation for an array of N integer data.
Mean is the sum of all the elements by number of elements i.e mean= ∑𝑖=0
𝑛−1
Xi/ n
Varience= ∑𝑖=0
𝑛−1
(𝑋𝑖 − 𝑚𝑒𝑎𝑛)2
n
Deviation=√𝑣𝑎𝑟𝑖𝑒𝑛𝑐𝑒
#include<stdio.h>

14
Void main( )
{
int x[100],n,i;
float mean, varience, deviation,sum;
scanf(“%d”,&n);
for(i=0;i<n;i++)
{
scanf(“%d”, &x[i]);
}
Sum=0;
for(i=0;i<n;i++)
{
sum=sum + x[i];
}
mean=sum/n;
printf(“mean=%f”,mean);
sum=0;
for(i=0;i<n;i++)
{
sum=sum+(𝑋𝑖 − 𝑚𝑒𝑎𝑛) * (𝑋𝑖 − 𝑚𝑒𝑎𝑛) ;
}
varience=sum/n;
deviation=sqrt(varience);
printf(“varience=%f”,varience);
printf(“deviation=%f”,deviation);
}

15
Searching techniques in C language
How to search an element in an array, whether an element is found in an array or not using
following techniques
• Linear Search
• Binary Search
Sorting Technique in C language
How to sort array elements in ascending order or descender order using the following
techniques
• bubble sort
• selection sort
Searching technique – Linear search
In linear search, searching an key element from the first position element, compare the first
position element with key element, if the first position element is matches with key element
then we can display search is successful and stop searching.
If the first position element is not matching with the key element, then compare with the
second position element with key element, if it is matches then display search is successful
and stop the searching. Once again second position element is not matching with key element
then comparison start with third element, this process will repeat until the end of the element
in an array.
#include<stdio.h>
Void main()
{
int a[100],n,key,I;
printf(“enter the size of the array”);
scanf(“%d”,&n;
for(i=0;i<n;i++)
{
}

16
printf(“enter the key element to be search”);
scanf(“%d”,&key);
//comparison from first element with key element
for(i=0;i<n;i++)
{
if(a[i]==key)
{
printf(“item is found”);
exit(0);
}
}
printf(“item is not found”);
}
Input1:
Enter the size of an array
4
10 20 40 30
Enter key element
20
Item is found
Input2:
4
10 20 40 30

17
Enter key element
70
Item is not found
Important Note: In the linear searching, input array elements to an array either in sorted
order or un-sorted order
Advantages in linear search
1. In linear search, read array elements in sorted order or un-sorted order.
Disadvantage in linear search
1. In linear search, number of comparison is more.
Binary Search
how the searching will be done in binary search????
In binary search, first we have to read array elements(i.e always in sorted order(i.e in
ascending or descending order)). Once we read array elements, first we have to find the mid
position element, then compare mid position element with key element, if mid position
element is matches with key element then we display item is found and stop searching the
element in an array. But if the mid position element is not matches with key element then we
verify whether key element is greater than the mid or the less than the mid.
If the key element is less the mid element, searching will be done in the left side otherwise
searching will be done in the right part.
So, In binary search, number of comparison is less and is one of the most efficient algorithm
#include<stdio.h>
Void main()
{
int a[100],n ,mid ,key, low, high, i;
scanf(“%d”,&n);
for(i=0;i<n;i++)
{

18
}
printf(“enter key to be search”);
scanf(“%d”,&key);
low=0;
high=n-1;
while(low<=high)
{
mid=(low+high)/2;
if(a[mid]==key)
{
printf(“item is found “);
exit(0);
}
If(key<a[mid])
high=mid-1;
else
low=mid+1;
}
printf(“item is not found”);
}
Input1:
4
10 20 40 30
Enter key element
20
Item is found

19
Input2:
4
10 20 40 30
Enter key element
60
Item is not found
Sorting techniques
Bubble sort
Selection sort
Bubble sort : how to sort the array elements in ascending or descending order
How the sorting will be done like this
In the first pass we will compare first element with second element, if the first position
element in the array is greater than second position element in the array, swap these two
elements in the array otherwise don’t swap, next compare second position elements with third
position element, if the second position element is greater than third position element, swap
those two elements otherwise don’t swap. This will repeat until the first ascending order
element is found . In the second pass, start compare the first position element with the second
position element, if the first position element is greater than second position element , swap
those two numbers otherwise don’t swap, this will repeat. Some sorting will take two passes
or some sorting will take three passes, number of passes will be depend on the complexity of
the problem.
#include<stdio.h>
Void main()
{
int a[100], n, i, temp;
printf(“enter the size of the array”);
scanf(“%d”,&n);
printf(“read array elements”);
for(i=0;i<n;i++)

20
{
}
for(j=1; j<n ; j++) //first for loop for the number of passes
{
for(i=0; i<n-j; i++) //comparison starts from the first position element
{
if(a[i]>a[i+1]) //compare first position element with second
{ position element
temp=a[i];
a[i]=a[i+1];
a[i+1]=temp;
}
}
}
printf(“sorted elements are……”);
for(i=0;i<n;i++)
{
}
}
Input1:
4
50 20 40 30
The sorted elements are…..
20 30 40 50

21
Selection Sorting Technique
In the selection sorting, how the sorting will be done ….first search the position where the
first sorted element is there in the array, once we search the first position element, we have to
placed in the first position similarly search the second position element in the array and place
the second position element in the second place, repeat the process until all the elements are
sorted in the proper order.
#include<stdio.h>
Void main( )
{
int a[100],n,i,,pos,temp;
printf(“enter the number of elements”);
scanf(“%d”,&n);
for(i=0;i<n;i++)
{
}
for(i=0;i<n-1;i++)
{
pos=i;
for(j=i+1;j<n;j++)
{
If(a[j]>a[pos])
pos=j;
}
temp=a[pos];
a[pos]=a[i];
a[i]=temp;
}
printf(“sorted elements are……”);
for(i=0;i<n;i++)

22
{
}
}
Input1:
4
50 20 40 30
The sorted elements are…..
20 30 40 50
Note: first we have to know how to read N names(or strings) or array of names.
Char a[5][10];
Number of names(or strings)
Length of the names
Size of an array = 5*10*1=50
0 1 2 3 4 5 6 7 8 9
R A M A 0
N I T H I N 0
K U M A R 0
A S H A 0
K A V A N A 0
In this manner array of names will be stored in the memory
How to read array of names is as follows:
Char a[5][10];
int i;
a[0]
a[1]
a[2]
a[3]
a[4]

23
printf(“read array of names”);
for(i=0;i<5;i++)
{
scanf(“%s”,a[i]);
}
How to display array of names
printf(“read array of names”);
for(i=0;i<5;i++)
{
printf(“%s n”,a[i]);
}
1. Write a C program to read N names and sort the names using bubble sort technique.
#include<stdio.h>
#include<string.h>
void main( )
{
char a[10][30],temp[30];
int n,i;
printf(“enter the N names”);
scanf(“%d”,&n);
printf(“read names”);
for(i=0;i<n;i++)
{
scanf(“%s”, a[i]);
}
//sort the names using bubble sort
for(j=1;j<n;j++)
{
for(i=0;i<n-j;i++)
{
if(strcmp(a[i],a[i+1])>0)
{
strcpy(temp,a[i]);
strcpy(a[i],a[i+1]);
strcpy(a[i+1],temp);
}
}

24
}
printf(“sorted names are………..”);
for(i=0;i<n;i++)
{
printf(“%sn”, a[i]);
}
}
Note: strcmp() and strcpy() are the string handling functions and these two functions are
present in <string.h>
Two -Dimensional array(2D)
2D array is a array with two subscripts is called 2D array.
How to declare 2D array
datatype arr_name[exp1][exp2];
exp1->number of rows
exp2->number of columns
int a[2][2]; //construct a matrix a with 2 rows and 2 columns
int b[3][4]; //construct a matrix b with 3 rows and 4 columns
how to find the size of the 2D array
int a[2][2];
size of the array a or size of the matrix a is= rows*columns*type of data
= 2*2*2
= 8 bytes
How was structure in the memory
how to initialize the 2D array
datatype arr_name[exp1][exp2]={{a1,a2,a3,……,an},
a[0][0] a[0][1]
a[1][0] a[1][1]
Row0
Row1
0 1
2 bytes
2 bytes
2 bytes
2 bytes

25
{b1,b2,b3,……,bn},
{c1,c2,c3,………..,cn},
-------------------------
{z1,z2,z3,…………,zn}};
Example:
int a[2][2]={{1,2},
{3,4}};
How it will be stored in the memory as given below
0 1
1 2
3 4
int a[3][4]={{10,20,30,40},
{50,60,70,80},
{90,100,110,120}};
0 1 2 3
10 20 30 40
50 60 70 80
90 100 110 120
Different ways of initializing 2D array
1. Initializing all specified memory location
2. Partial array initialization
Initializing all specified memory locations
Example:
int a[3][4]={{5,20,3,4},
{50,60,90,80},
{1, 2, 7, 8} } ;
Row 0
Row 1
Row 0
Row 1
Row 2

26
0 1 2 3
5 20 3 4
50 60 90 80
1 2 7 8
Partial array initialization
Example:
int a[3][3]={{10,20},
{30},
{40,50}};
How the data will be stored in the memory as given below in the table
0 1 2
10 20 0
30 0 0
40 50 0
How to read the matrix elements
int a[2][2]; i.e 2-rows and 2-columns
size of the array a is =2*2*2=8 bytes
coll 0 coll1
for(i=0;i<2;i++) // i for rows
{
for(j=0;j<2;j++) //j for columns
{
scanf(“%d”,&a[i][j]);
Row 0
Row 1
Row 2
Row 0
Row 1
Row 2
Row 0
Row 1
2 bytes
2 bytes 2 bytes
2 bytes

27
}
}
How to display matrix elements
for(i=0;i<2;i++) // i for rows
{
for(j=0;j<2;j++) //j for columns
{
printf(“%d ”,a[i][j]);
}
Printf(“n”);
}
How to read and display matrix elements(i.e read 2X2 matrix)
#include<stdio.h>
Void main( )
{
Int a[2][2],i,j;
printf(“read matrix a elements”);
for(i=0;i<2;i++)
{
for(j=0;j<2;j++)
{
}
}
printf(“matrix a elements are……..”);
for(i=0;i<2;i++)
{
1 2
2 3
Read matrix a elements
matrix a elements are……

28
for(j=0;j<2;j++)
{
}
printf(“n”);
}
}
How to read and display matrix whose order is 4X4
#include<stdio.h>
Void main( )
{
int a[4][4],i,j;
for(i=0;i<4;i++)
{
for(j=0;j<4;j++)
{
}
}
printf(“matrix a elements are……..”);
for(i=0;i<4;i++)
{
for(j=0;j<4;j++)
{
}
printf(“n”);
1 2
2 3
1 2 3 4
5 6 7 8
9 10 11 12
matrix a elements are……
1 2 3 4
5 6 7 8
9 10 11 12

29
}
}
1. Write a C program to read and display a matrix whose order is mXn
#include<stdio.h>
void main( )
{
int a[10][10], i, j,m, n;
printf(“enter the order(mXn) of the matrix”);
scanf(“%d%d”,&m,&n);
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
}
}
printf(“matrix elements are….”);
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
}
printf(“n”)
}}
enter the order(mXn) of the matrix
2 2

30
3 4
4 6
matrix elements are……
3 4
4 6
2. Write a C program by reading matrix and find the sum of all the elements in a
matrix.
#include<stdio.h>
void main( )
{
int a[10][10], m, i, j, n,sum;
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
}
}
sum=0;
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
sum=sum+a[i][j];
}
}

31
}
Output:
2 2
1 4
2 6
Sum=13
3. Write a C program by reading a matrix and find the first largest element in that
matrix
#include<stdio.h>
void main( )
{
int a[10][10], m, n,big,i,j;
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
}
}
big=a[0][0];
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)

32
{
If(a[i][j]>big)
{
big=a[i][j];
}
}
}
printf(“the biggest element is=%d”,big);
}
Output:
2 2
1 2
5 9
The biggest element is = 9
4. Write a C program by reading a matrix and find its transpose matrix
Note: Transpose matrix is interchanging of rows and columns
#include<stdio.h>
void main( )
{
int a[10][10], m, n,big,i,j;
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)

33
{
}
}
printf(“ transpose matrix is……….”);
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
printf(“%d “, a[j][i]);
}
printf(“n”);
}
1 2
3 4
5 6
Transpose matrix is……..
3 5
4 6
5. Write a C program by reading a matrix and find sum of each row
#include<stdio.h>
void main( )
{
int a[10][10], m, n,sum,i,j;

34
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
}
}
for(i=0;i<m;i++)
{
sum=0;
for(j=0;j<n;j++)
{
sum=sum+a[i][j];
}
printf(“sum of %d row= %d”,i+1,sum);
}
}
Output
2 2
1 2
3 4
Sum of 1 row is = 3
Sum of 2 row is = 7
6. Write a C program by reading a matrix and find the sum of each column
#include<stdio.h>
void main( )

35
{
int a[10][10], m, n,sum,i,j;
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
}
}
for(i=0;i<m;i++)
{
sum=0;
for(j=0;j<n;j++)
{
sum=sum+a[j][i];
}
}
}
Output
2 2
1 2
3 4
Sum of 1 column is = 4

36
Sum of 2 column is = 6
7. Write a C program by reading a matrix and find sum of each row and sum of
each column
#include<stdio.h>
void main( )
{
int a[10][10], m, n,sum,i,j;
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
}
}
// sum of each row
for(i=0;i<m;i++)
{
sum=0;
for(j=0;j<n;j++)
{
sum=sum+a[i][j];
}
}
//sum of each column

37
for(i=0;i<m;i++)
{
sum=0;
for(j=0;j<n;j++)
{
sum=sum+a[j][i];
}
printf(“sum of %d column= %d”,i+1,sum);
}
}
Output
2 2
1 2
3 4
Sum of 1 row is = 3
Sum of 2 row is = 7
Sum of 1 column = 4
Sum of 2 column = 6
8. Write a C program by reading a matrix and find the trace of a matrix
Note:trace of a matrix is the sum of the principal diagonal elements
#include<stdio.h>
void main( )
{
int a[10][10], m, n,sum,i,j;

38
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
}
}
sum=0;
for(i=0;i<m;i++)
{
sum=sum+a[i][i];
}
printf(“trace of the matrix is=%d”,sum);
}
Output
2 2
1 2
3 4
trace of the matrix is = 5
9. Write a C program by reading a matrix and find the norm of the matrix
(Note: Norm of a matrix is the square root of the sum of the squares of all the elements
in a matrix)
#include<stdio.h>
void main( )
{
int a[10][10], m, n, sum,i,j;

39
float nsum;
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
}
}
sum=0;
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
sum=sum+a[i][j]*a[i][j];
}
}
nsum=sqrt(sum);
printf(“nsum = %f ”, nsum);
}
Output
2 2
1 2
3 4
nsum = 5.47722557

40
10. Write a C program to perform addition of two matrix
#include<stdio.h>
void main( )
{
int a[10][10],b[10][10],c[10][10], m, n, i, j;
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
}
}
printf(“read matrix b elements”);
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
scanf(“%d”,&b[i][j]);
}
}
// sum of two matrix
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
c[i][j]=a[i][j]+b[i][j];

41
}
}
printf(“C matrix is ………………..”);
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
printf(“%d ”,c[i][j]);
}
printf(“n”);
}
}
Output:
2 2
1 2
3 4
Read matrix b elements
1 2
3 4
C matrix is……….
2 4
6 8
11. Write a C program to perform subtraction of two matrix
#include<stdio.h>
void main( )
{

42
int a[10][10],b[10][10],c[10][10], m, n, i, j;
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
}
}
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
}
}
// sum of two matrix
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
c[i][j]=b[i][j]-a[i][j];
}
}
for(i=0;i<m;i++)

43
{
for(j=0;j<n;j++)
{
}
printf(“n”);
}
}
Output:
2 2
1 2
3 4
7 8
9 10
6 6
6 6
12. Write a C program to perform multiplication of two matrix
#include<stdio.h>
void main( )
{
int a[10][10],b[10][10],c[10][10], m, n, p, q ,i, j, k,sum;

44
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
}
}
printf(“enter the order(pXq) of the matrix”);
scanf(“%d%d”,&p,&q);
for(i=0;i<p;i++)
{
for(j=0;j<q;j++)
{
}
}
// multiplication of two matrix
for(i=0;i<m;i++)
{
for(j=0;j<q ; j++)
{
sum=0;
for(k=0;k<n ; k++)
{
sum=sum+a[i][k]*b[k][j];
}
c[i][j]=sum;
}

45
}
for(i=0;i<m;i++)
{
for(j=0;j<q ;j++)
{
}
printf(“n”);
}
}
Output:
2 2
1 2
3 4
enter the order(pXq) of the matrix
2 2
1 2
3 4
7 10
15 22

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