#include <iostream>
using namespace std;
int main()
{
int i, n;
// read n from the user
cin >> n;
// print out all numbers <=n that are divisible by 3
// approach 1
cout << "Approach 1:" << endl;
for (i = 1; i <= n; i++)
if (i%3 == 0)
cout << i << endl;
// approach 2
cout << "Approach 2:" << endl;
for (i = n; i > 0; i--)
if (i%3 == 0)
cout << i << endl;
// approach 3
cout << "Approach 3:" << endl;
for (i = 3; i <= n; i+=3)
cout << i << endl;
// approach 4
cout << "Approach 4:" << endl;
for (i = n-n%3; i > 0; i-=3)
cout << i << endl;
return 0;
}
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