Basic While loops

[fapyfapy]

I'm trying to make a program in which you enter a number (n) and it prints (n-1) spaces followed by the "k" then on the next line, (n-2) spaces followed by "k" and so on until "k" has no spaces before it.

#include <iostream>
using namespace std;
 
int main ()
{
	int len;

	cout << "Enter a number: ";
	cin >> len;

   int i = 0;
   int j = i + 1;
  
   while (i < len)
   {
	   while (j < len)
	   {
		   cout << " ";
		   j++;
	   }
	   i++;
	   cout << "#" << endl;
   }

   return 0;
}

[giblit]

so basically loop while there are more than 1 spaces and the initial space is n - 1.

int n;

cout << "Enter n: ";
cin >> n;

--n;

while( n ) //loop while n is not 0
{
    for( int i = 0; i < n; ++i ) //can you use for?
        cout << ' ';
    cout << 'K' << endl;
    --n;
}
cout << 'K' << endl;

or instead of that while loop

while( n > -1 )
{
    for( int i = 0; i < n; ++i )
        cout << ' ';
    cout << 'K' << endl;
    --n;
}

Or you could just use 2 for loops.


[edit]Also int j = i + 1; is the same as int j = 1; in this case since i == 0.

actually you can ignore my code and just move line 12 inside of the first while loop :) You forgot to reset the value of j each time.

  
   while (i < len)
   {
        int j = i + 1;
	   while (j < len)
	   {
		   cout << " ";
		   j++;
	   }
	   i++;
	   cout << "#" << endl;
   }

[fapyfapy]

Thanks very much, on another note, I am trying to do the same thing but with do while loops.

#include <iostream>
using namespace std;

	int main()
	{
	    int len;

	    cout << "Enter a number: ";
	    cin >> len;

	   int i = 0;
	   do 
	   { 
		   int j = i + 1;
		   do
		   {
			   cout << " ";
			   j++;
		   } while( j < len );
		   
		   cout << "#" << endl;
		   i++;
	   } while( i < len );

	}

It seems to be almost correct but for some reason it is printing a " " even when j=len. This should not happen since the do while loop specifies j<len?

[TwilightSpectre]

A do-while loop will ALWAYS execute at least once. Of you don't want this to happen, just use the normal 'while' loops.

[fapyfapy]

Thanks both giblit and NT3 for clearing those things up!

[Yanson]

to make things easier you can use the setw function
http://www.cplusplus.com/reference/iomanip/setw/?kw=setw

#include <iostream>
#include <iomanip>
using namespace std;

int main()
{
    int num = 0;

    //gets data from user
    cout << "Please enter an Integer: " << flush;
    cin >> num;

   //print
    while(num > 0)
    {
        cout << setw(num) << '#' << endl;
        num--;
    }

    cin.ignore();
    return 0;

}