reverseArray3.js (*** Two Pointer Approach***)

 /* Reverse of an Array by two pointer approach

Given

A =[5,8,7,3,10]

Output

A=[10,3,7,8,5]

*/

/////////////////////////////////////////////////////////////////////////////////////////////////////////

//index 0 1 2 3 4

let A = [5, 8, 7, 3, 10];

let p = 0; // intialising while loop

let q = A.length - 1; //intialising while loop i.e 4

while (p < q) // 1) p =0 < q=4 true , 2) p=1 < q=3 true , etc....

{

let temp = A[p]; // 1) temp = 5 , 2) temp = 8

A[p] = A[q]; // 1) A[p]= 10 , 2) A[p]= 3

A[q] = temp; // 1) A[q]= 5 , 2) A[q]= 8

p++ //increment of while loop , 1)p=1 2) p=2 etc...

q-- //decrement of while loop , 1) q=3 2) q= 2 etc...

}

console.log(A);

T.C= o(n/2)

= o(n)

S.C = o(1)

//////////////////////////////////////////////////////////////////////////////////////////////

TERMINAL: