Two Pointer Technique

/**There are Given a sorted array.For this we search if there exists any pair of

   elements(a[i], a[j]) such that their sum is equal to x. Here We Use Two Pointer Technique.**/

#include<bits/stdc++.h>

using namespace std;

int main()

{

int n;

cout << "Enter Array Size :: ";

cin >> n;

int a[n], x;

cout << "\nEnter Array Element :: ";

for(int i=0;i<n;i++)   /// Example : {2, 3, 5, 8, 9, 13, 15}

cin >> a[i];

sort(a, a+n);  /// For Sort Array Element Ascending Order

cout << "\nEnter Which Element you search :: ";

cin >> x;   /// Example : 14

int i = 0, j = n-1; /// Start Two Pointer Technique

int f = 0; /// flag variable for reminder

while(i<j)

{

if(a[i] + a[j] == x)

{

f = 1;

break;

}

else if(a[i] + a[j] < x)

i++;

else

j--;

}

if(f == 0)

cout << x << " Not Found" << "\n";

else

cout << x << " is Found" << "\n";

return 0;

}