**Linear Search**is the one of the basic search algorithm used in

**computer science**. This is also called

**brute force**searching algorithm, because, it just starts the searching each element in the array from starting position until

*key*found or end of the array. Here the advantage is with this algorithm is that array of elements can be any order where as in

**binary search**the elements should be in sorted order. This searching algorithm will be useful if the no. of elements in the array are less or small.

**Algorithm for linear search:**

1

**.**Get the element

*key*which needs to be search in the array

2. Get the array of the elements in which

*key*needs to be search

3. take the elements from position zero in the array

4. compare the element with

*key*matches stops the process

5. if not matches proceed for the next element until end of the array

6. repeat steps from 3 to 6

**Time Complexity of Linear Search:**The best case for this searching algorithm is

**O(1).**Because , we may get the searchin

*key*in the first position itself. And the worst case of linear search algorithm is

**O(n).**Because we may get the searching

*key*in the last position in the array or we may not get the

*key*element in the array. Because of this complexity, its not advisable to use this searching algorithm if the no. of eleaments in the array more(probabley more than 100).

**Program of linear search in C:**

int linear_search(int arr[], int key, int max_pos) { int pos; for(pos=0;pos<max_pos;pos++) { if(arr[pos]==key) return pos; } return -1; } main() { int arr[10],i,pos,key; int startIndex=0; int endIndex=9; printf("enter the elements in array in sorted orderd only\n"); for(i=0;i<10;i++) { scanf("%d",&arr[i]); } printf("enter the element to be searched\n"); scanf("%d",&key); pos = linear_search(arr,key,endIndex); if(pos!=-1) printf("element %d find at position %d\n",key,pos); else printf("element not in the array\n"); }

**Results:**

enter the elements in array in sorted orderd only

234

45

56

78

90

12

23

123

534

765

enter the element to be searched

534

element 534 find at position 8

enter the elements in array in sorted orderd only

234

34

45

56

67

89

90

12

23

34

enter the element to be searched

1234

element not in the array