/* To demonstrate for loops.
 * The sybtax of the for loop is : for(initialization ; condition ; incrememt)
 * 				   {
 * 				   	loop body
 * 				   }
 * initialization is done only once, at the beginning of the loop.
 * Then, the condition is checked. If it is false, it moves on to the next line after the loop.
 * If it is true, the loop body is executed and then the increment is executed.
 * Then the condition is checked once again, and then the whole process is repeated.
 *
 * The scope of a variable is the area of code where the vaiable is "alive"
 * Usually, this is from the line where the variable is declared, until the next }
 * For a for loop, if a variable is declared in the initialization part of the loop,
 * it is alive only unitl the end of the loop.
 */
#include<iostream>

using namespace std;

int main()
{
	/*int j=1;
	//this will bork your computerif it runs long enough
	while( j<= 100)
	{
		cout<<i<<endl;
	}*/

	//sum of first 10 natural numbers
	int sum =0;
	for (int i =1; i<=10; i++) 
	{
		sum+=i;
	}
	cout<<"The sum of the first 10 natural numbers is "<< sum << endl;
	//cout<<"i is "<<i<<endl;
	//would have caused error. i is out of scope
	

	//Print 20 through 1 in descending order
	for(short i =20 ; i>=1; i--)
	{
		cout<<i<<endl;
	}
	//Make sure you decremt instead of increment if you're counting down.
	//Otherwise, it will loop until overflow occurs.	
	cout<<endl<<endl;

	//Print the first 100 multiples of 5
	//The initialization and increment part of the for loops can have
	// several comma separated statements. 
	// The 3 parts of the loop: initialization, condition and incrementing
	// are themselves separeated by semicolons.

	for(int i=1, print = 5; i<=100; i++, print+=5)
	{
		cout<<print<<" ";
	}

	char ans;

	cout<<endl<<endl;
	cout<<"Is your question \"Is this the Krusty Krab?\" (Y or N): ";
	cin>>ans;
	//The 3 parts of the for loop are optional, but the semi colons are mandatory.
	//Here, we skip the initialization and increment parts because we aren't counting anything.
	for( ; ans == 'Y' ; )
	{
		cout<<"No, this is Patrick!!"<<endl;
		cout<<"Is your question \"Is this the Krusty Krab?\" (Y or N): ";
		cin>>ans;
	}

	//Th find and print the factorial of a number
	long fact = 1;
	int num;

	cout<<"Enter a positive integer: ";
	cin>> num;

	for(int i=1; i<=num; i++)
		fact *= i;

	cout <<"The factorial is "<< fact<<endl;

	int j=1;
	
	//Example for break and continue
	for( ; ; )
	{
		cout<<"j is "<<j<<" ";
		
		if(j==8)
			break;
		j++;

		if( j==2 || j==4)
		{
			cout<<"We continue"<<"\t";
			continue;
		}
		cout<<endl;
		
	}

	cout<<endl;

	// loops can be nested. The following construct prints a rectangle
	int rows =3;
	int col = 6;
	//Outer loop prints one row per iteration
	for(int i=0; i<rows; i++)
	{
		//inner loop prints each character in a row
		for(int j=0; j<col; j++)
		{
			cout<<"*";
		}
		cout<<endl;
	}


	return 0;
}