Thread: C++ Pattern Help

  1. #1
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    C++ Pattern Help

    Hellow forum. I am new to the forum but would like some help. I am new to c++ studying it at a Univercity(just started). But i need help with a question i got in our new program set.\

    4. Write a program that displays the following pattern

    *
    **
    ***
    ****
    *****
    ******
    *******
    ********

    Your program may use ONLY three types of output statements, one of each of the following forms:
    cout << “* “;
    cout << “ “;
    cout << endl;

    You must use a loop to solve this problem. The type of loop you choose to use is up to you. You cannot submit a solution that does not use looping of some form.

  2. #2
    C++ Witch laserlight's Avatar
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    What have you tried, or at least what do you have in mind?
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way

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    Well... so far i think i need to use 2 nested while loops....one for counting down (the outer most loop) and the other for counting across (the inner most loop).

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    So write the code for main and the loops and get it to compile and run (even if it does nothing). Then once that's working you can work on getting it to display the *'s correctly.

  5. #5
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    Code:
    #include <iostream>
    using namespace std;
    
    int main(){
    	
    	for( int i = 0; i < 10; i++ ){
    	
    		for(int x = 0; x < i+1; x++){
    			cout<<"*";
    		}
    		cout<<endl;		
    	}
    	
    	return 0;	
    }
    But the ** displays the wrong direction

  6. #6
    C++ Witch laserlight's Avatar
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    But the ** displays the wrong direction
    The code looks okay. I went so far as to test it, and it appears to work just as your assignment described.
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way

  7. #7
    Frequently Quite Prolix dwks's Avatar
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    If you wanted a pattern like this:
    Code:
      *
     **
    ***
    then you'd just have to print 10-i spaces before you go printing asterisks.
    dwk

    Seek and ye shall find. quaere et invenies.

    "Simplicity does not precede complexity, but follows it." -- Alan Perlis
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  8. #8
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    >> But the ** displays the wrong direction
    Put the assignment (or the example) in code tags, not quote tags, to make sure it displays properly in the forum. I assume that you want it like dwks showed, but if not then you'll have to post the example again so that the leading spaces aren't removed by the forum software.

  9. #9
    Frequently Quite Prolix dwks's Avatar
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    Put the assignment (or the example) in code tags, not quote tags, to make sure it displays properly in the forum. I assume that you want it like dwks showed, but if not then you'll have to post the example again so that the leading spaces aren't removed by the forum software.
    Just the example. Otherwise those long lines of text would run off the edge of the screen, if you had a reasonably small monitor.

    BTW, "x <= i" might be easier to read than "x < i+1".
    dwk

    Seek and ye shall find. quaere et invenies.

    "Simplicity does not precede complexity, but follows it." -- Alan Perlis
    "Testing can only prove the presence of bugs, not their absence." -- Edsger Dijkstra
    "The only real mistake is the one from which we learn nothing." -- John Powell


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  10. #10
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    Quote Originally Posted by dwks View Post
    If you wanted a pattern like this:
    Code:
      *
     **
    ***
    then you'd just have to print 10-i spaces before you go printing asterisks.

    How could i do that?

  11. #11
    Frequently Quite Prolix dwks's Avatar
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    Umm . . . so you need 10-i spaces. How do you create a loop that loops 10-i times?

    The loop
    Code:
    for(x = 0; x < N; x ++)
    loops N times, so how do you think you loop 10-i times?
    dwk

    Seek and ye shall find. quaere et invenies.

    "Simplicity does not precede complexity, but follows it." -- Alan Perlis
    "Testing can only prove the presence of bugs, not their absence." -- Edsger Dijkstra
    "The only real mistake is the one from which we learn nothing." -- John Powell


    Other boards: DaniWeb, TPS
    Unofficial Wiki FAQ: cpwiki.sf.net

    My website: http://dwks.theprogrammingsite.com/
    Projects: codeform, xuni, atlantis, nort, etc.

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