2. Topics to be covered  Introduction to array Introduction to array  Types of array Types of array  One dimensional array One dimensional array  Declaration of an array Declaration of an array  Initialization of an array Initialization of an array  Reading and Writing an array Reading and Writing an array  Programs of One dimensional Array Programs of One dimensional Array

3. What is Array An array is a collection of data elements that are of the same type (e.g., a collection of integers, collection of characters, collection of doubles).

4.  Array ◦ Group of consecutive memory locations ◦ Same name and type  To refer to an element, specify ◦ Array name ◦ Position number  Format: arrayname[ position number ] ◦ First element at position 0 ◦ n element array named A:  A[ 0 ], A[ 1 ]...A[ n – 1 ] 4 6 3 2 A[0] A[1] A[2] A[3] Back

5. Types of Arrays 1. One dimensional Array 2. Two dimensional Array 3. Multidimensional Array Back

6. One Dimensional Array One dimensional Array: An array in which each individual element can be refer by one subscript is called one dimensional array. Back

7. Declaration of an array Syntax: type arrayname[array_size]; Example: int A[10]; The array elements are all values of the type type. The size of the array is indicated by array_size, the number of elements in the array. array_size: must be an int constant or a constant expression. Note that an array can have multiple dimensions.

8. Declare an array of 10 integers: int A[10]; To access an individual element we must apply a subscript to array named A. A subscript is a bracketed expression. The expression in the brackets is known as the index. First element of array has index 0. A[0] Second element of array has index 1, and so on. A[1], A[2], A[3],… Last element has an index one less than the size of the array. A[9] Back

9. Initialization of an array int n[ 5 ] = { 1, 2, 3, 4, 5 }; If not enough initializers, rightmost elements become 0 int n[ 5 ] = { 0 } ; All elements 0 The array size need not be specified explicitly. When initial values are include as a part of definition, the array will automatically set equal to the number of initial values included in the definition. int a[]={2,1,3,5,4}; Size=5; Back

10. Reading & Writing an Array Reading an array: An array can be read by reading the elements inside a loop that iterates as many times as there are elements in the array. For loop is generally used for this purpose for(i=0;i<n;i++) Scanf(“%d”,&a[i]); Writing an array: An array can be written by writing the elements inside a loop that iterate as many times as there are elementsin the array. For loop is generally used for this purpose. for(i=0;i<n;i++) printf(“%d”,a[i]); Back

11. Programs of one dimensional array 1)Searching Linear Search Binary Search 2) Sorting Bubble Sort Selection Sort Back

12. Program for Linear Search #include void main() { int a[20],i,n,d,c=0; clrscr(); printf("\n enter the value of n"); scanf("%d",&n); printf("\n enter the element"); for(i=0;i<n;i++) { scanf("%d",&a[i]); } printf("\n enter the element to be searched"); scanf("%d",&d);

13. for(i=0;i<n;i++) if(a[i]==d) { printf("\n elements found at location%d",i+1); c++; } if(c==0) printf("Element not found"); getch(); } Back

14. Program for Binary Search #include void main() { int a[10],i,n,m,b,e,d; clrscr(); printf("Enter the size of an array"); scanf("%d",&n); printf("\nEnter the elements of the array"); for(i=0;i<n;i++) { scanf("%d",&a[i]); } printf("\nThe elements of an array are"); for(i=0;i<n;i++) { printf(" %d",a[i]); }

15. printf("\nEnter the number to be search"); scanf("%d",&d); b=0; e=n-1; m=(b+e)/2; while((a[m]!=d)&&(b<=e)) { if(a[m]<d) b=m+1; else e=m-1; m=(b+e)/2; } if(a[m]==d) printf("Element is found at position%d",m+1); else printf("Element is not found"); getch(); } Back

16. Program for Bubble Sort #include main() { int nums[5]; int i,j,temp,n; clrscr(); printf("Enter size of an array"); scanf("%d",&n); printf("\n enter the array element"); for(i=0;i<n;i++) { scanf("%d",&nums[i]); }

17. //BUBBLE SORTING for(i=0;i<n-1;i++) for(j=0;j<n-1-i;j++) if(nums[j]>nums[j+1]) { temp=nums[j]; nums[j]=nums[j+1]; nums[j+1]=temp; } printf("\n\n\t the sorted array is \n"); for(i=0;i<n;i++) { printf("\t%d",nums[i]); } getch(); } Back

18. Program for Selection Sort #include void main() { int nums[20]; int i,j,small,sp,t,n; clrscr(); printf("Enter value of n"); scanf("%d",&n); printf("\n enter the array element"); for(i=0;i<n;i++) { scanf("%d",&nums[i]); }

19. //SELECTION SORTING for(i=0;i<n-1;i++) {small=nums[i]; sp=i; for(j=i+1;j<n;j++) if(nums[j]<small) { small=nums[j]; sp=j; } t=nums[i]; nums[i]=nums[sp];//swapping nums[sp]=t; } printf("\n\n\t the sorted array is \n"); for(i=0;i<n;i++) {printf("\t%d",nums[i]);} getch();} Back Back

20. Thanks