Explain anyone

Question

#include <iostream>
using namespace std;

int main() {
int array[]={1,3,5,7,8};
int i,k=3,j,n=5;
int item=10;j=n;

cout<<"original array element"<<endl;

for(i=0;i<n;i++)
{
cout<<"array["<<i<<"]"<<array[i]<<endl;
}

n=n+1;

while(j>=k)
{
array[j+1]=array[j];
j=j-1;
}
array[k]=item;

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

cout<<"new array["<<i<<"]="<<array[i]
<<endl;

}

return 0;
}

Answer 1

n is 6 and k is 3
j is 5
j is decremented and
array[6] = array[5]
array[5]= array [4]
array[4]= array [3]
and
array[k] = item // array[3] = 10

Answer 2

doubt is

n=n+1;

while(j>=k)
{
array[j+1]=array[j];
j=j-1;
}
array[k]=item;

how it's working