X patterns

[uoJhf]

Hello there.. i'm kind of new in c++ and i really suck in programming. so here is the thing. My professor left us with an assignment and i managed to do some things on my own. Here is the problem:

i should write a program that will accept a user entered number this could be any integer. The program will draw a pattern x of whose size is dependent on the user-defined number. A sample entry and corresponding output is shown below:
Input number: 3
output:
x x
 x
x x

Input number: 5
output:
x...x
.x.x.
..x..
.x.x.
x...x

(nevermind the dots in input number 5, it represents spaces)

*i've done the part when you have inputed even numbers it will print invalid and blah blah blah. i'm also finished in the first lines of the output
*my problem is the succeeding lines..
*and the worst prolem is.. i should base my program in the for statement.

anyone's help will be greatly appriciated. thank you

[Bazzy]

You should have two loops, one for the coulumn position and one for the row position.
eg:

for(int y = 0; y < user_input; y++)
{
     for(int x = 0; x < user_input; x++)
           //here you should put the condition and draw an 'X' or a space
     cout << '\n';// end of row so go to a new line
}

for the condition notice that in (input == 7)
│0123456 (x position)
0│x x
1│ x x
2│ x x
3│ x
4│ x x
5│ x x
6│x x
(y position)


the 'X' depends on x and y position

[uoJhf]

cool.. thx :D

umm.. can anyone try it on a different approach in a for statement?

[demosthenes2k8]

That is in a for statement. Try actually reading it.
You didn't even notice the correlation between x and y when you chart an X?

If you had looked at that, maybe you would understand that the person who posted above you ALREADY GAVE YOU THE ANSWER.

[uoJhf]

duh, i know what a for statement looks like, what i meant is.. is there another way for a for statement to be written?

[Bazzy]

What you mean with "is there another way for a for statement to be written" ?

You could use the for statement as you want (according to its format), for more documentation read
http://www.cplusplus.com/doc/tutorial/control.html#for

[seymore15074]

This assignment made me think for a minute; consider this:

Find the equations of the two lines and create a function for each. Then iterate through the view-plane testing for valid coordinates and plot the 'x' where appropriate. That way, you could actually plot other lines if you someday desired.

[grey127]

can you give some sample .... @ ABOVE

[Bazzy]

When you choose whether to print an 'x' or a space you should use as condition the equation of the two lines.
In the 'x' example the equations are:
y = x
and
y = -x + 6

[seymore15074]

The slope-intercept form of an equation of a line is y = mx + b, where m is the slope of the line and b is the intercept. (I think it's the X-intercept, but I could be wrong; it's the one where the X coordinate is 0)

/*
    Create a class to represent a line that stores two doubles: _m (the slope) and _b the intercept.
*/

// add a member to return the unique Y coordinate given a specific X, such as:
double Y( double x ) {
    return _m * x + _b;
}

In the traversal of the Cartesian view-plane, if the current y == line.Y( x ) then you are at a point that resides on the line.

This could be extended to support construction from a point on the line and a slope, as well. It's a neat application of the stuff that they teach you in math courses and don't use. ;)

[firedraco]

I think it's the X-intercept

It's the y-intercept, but otherwise you are right.