Binary Search.

 #include<iostream>

using namespace std;

void inputArray(int a[],int n);

void bubbleSort(int a[],int n);

int binarySearch(int a[],int n,int key);

int main()

{

int a[250];

int n;

int key;

int ans;

cout<<"\nENTER THE SIZE OF AN ARRAY: ";

cin>>n;

inputArray(a,n);

bubbleSort(a,n);

cout<<"\n enter the key: ";

cin>>key;

ans = binarySearch(a,n,key);

if(ans!=-1)

{

cout<<" \nElement is found. ";

}

else

cout<<" \nElement is not found";

}

void inputArray(int a[],int n)

{

for(int i=0;i<n;i++)

{

cout<<"\nENTER THE AN ARRAY: ";

cin>>a[i];

}

}

void bubbleSort(int a[],int n)

{

int temp;

for(int i=0;i<n-1;i++)

{

for(int j=0;j<n-1-i;j++)

{

if(a[j]>a[j+1])

{

temp=a[j];

a[j]=a[j+1];

a[j+1]=temp;

}

}

}

}

int binarySearch(int a[],int n,int key)

{

int low;

int high = n-1;

while(low<=high)

{

int mid = (low+high)/2;

if(a[mid]==key)

return mid;

else if(a[mid]<key)

low = mid+1;

else

high = mid - 1;

}

return -1;

}