#include <iostream>
using namespace std;
int main() {
// Program 1: Simple for loop
for (int i = 0; i < 5; ++i) {
cout << i << " ";
}
cout << endl;
// Program 2: Nested for loop
for (int i = 0; i < 3; ++i) {
for (int j = 0; j < 4; ++j) {
cout << i << "," << j << " ";
}
cout << endl;
}
// Program 3: While loop
int counter = 0;
while (counter < 3) {
cout << counter << " ";
++counter;
}
cout << endl;
// Program 4: Do-while loop
int num = 0;
do {
cout << num << " ";
++num;
} while (num < 4);
cout << endl;
return 0;
}