Javascript program to find the Intersection of Two unsorted Arrays

Intersection is the common elements which present in both the arrays

Solution Steps:-

Step 1: We sort  both the arrays 

Step 2: We use two pointers i and j initialize both with zero.

Step3:Now we run loop while i<m and j<n and compare each element present in  arr1 and arr2

Step4:  

• if(arr1[i]==arr2[j]) we add arr1[i] element to arr3 and increment both ptr i,j.
• if(arr1[i]>arr2[j]  we increment j
• if(arr[i]<arr2[j] we  increment i

Finally we print arr3

PROGRAM :

let arr1=[1,3,2,5,66,55];

let arr2=[1,2,4,0,22,55,88,66];

let m=arr1.length;

let n=arr2.length;

// array to store common elements

let arr3=[];

// sort arrays

arr1.sort();

arr2.sort();

let i=0,j=0;

let cnt=0;

while(i<m && j<n){

if(arr1[i]==arr2[j]){

arr3[cnt]=arr1[i];

cnt++;

i=i+1;

j=j+1;

}

else if(arr1[i]>arr2[j]){

j=j+1;

}

else if(arr1[i]<arr2[j]){

i=i+1

}

}

console.log(arr3)

let arr1=[1,3,2,5,66,55]; let arr2=[1,2,4,0,22,55,88,66]; let m=arr1.length; let n=arr2.length; let arr3=[]; arr1.sort(); arr2.sort(); let i=0,j=0; let cnt=0; while(i<m && j<n){ if(arr1[i]==arr2[j]){ arr3[cnt]=arr1[i]; cnt++; i=i+1; j=j+1; } else if(arr1[i]>arr2[j]){ j=j+1; } else if(arr1[i]<arr2[j]){ i=i+1 } } console.log(arr3)

OUTPUT :

Complexity

Time Complexity : O(MlogN)
Space Complexity : O(N)