[king1]

i am new at c++ and i a trying to write a program tha outputs the following but to look center alinged:

*
***
*****
*******
am also trying on a prog that can reverse numbers i.e 456362 to be 263654

[BanditFlyer]

Sounds like a pretty simple program. How much code have you written so far?

[king1]

this is what i have for the stars, but it cant aling it center
for the inversion of numbers am stuck


int z, a;

printf("please enter the number of rows you want: ");
z = GetInteger();
for(int i = 1; i <= z; i++)
{
a +=2;
for(int a = 0; a < i; a++)
{
printf("*");
}
printf("\n");
}

[BanditFlyer]

Originally Posted by king1

this is what i have for the stars, but it cant aling it center
for the inversion of numbers am stuck


int z, a;

printf("please enter the number of rows you want: ");
z = GetInteger();
for(int i = 1; i <= z; i++)
{
a +=2;
for(int a = 0; a < i; a++)
{
printf("*");
}
printf("\n");
}

I would throw in another integer for the number of spaces to prepend. Then whenever you print, you would subtract two from the spaces integer, s , so that the next line of print would be two spaces over to the left.

I would start the new integer, s, as being equal to z. Then, do another loop which prints spaces before you run the loop that prints asterisks. Keep printing spaces until you've printed as many as the current value of s.


As far as inverting numbers, normally that would be done with a stack, but you can do it with a loop also. Take a single digit off of the rear of the number that was input(I think you can do this with the mod operator) and append it to the rear of a new string. Keep doing that until you have no resuts from the mod operation.

[king1]

i really dont know where to put it

[dquigley]

Breaking down the problem and knowing where to "put it" is the point of the lesson.

Break down the problem like this:

1) Draw out the desired output for 4 or so rows
2) Make observations
3) Derive code that matches the observations

/*

when rows = 4

Desired Output:

   *        spaces before the stars = 3, stars = 1, total length = 4
  ***       spaces before the stars = 2, stars = 3, total length = 5
 *****      spaces before the stars = 1, stars = 5, total length = 6
*******     spaces before the stars = 0, stars = 7, total length = 7

Observe:
a) spaces decrement by 1 four times (same number as rows) but start at 3 and end at 0
b) stars start at 1 then increment four times but by odd numbers
c) the total length of the printout for each row starts equal to 
   rows then increments by one (probably not useful)


Derive code:

int rows = 4;
int spaces = rows - 1;   // spaces start at rows - 1;
int stars = 1;           // stars start at 1
do
    // do print out here         

    stars+=2;           // inc stars by two (will always be odd since we start at 1)
    spaces--;           // dec spaces;
    rows--;             // dec rows;
while(rows>0);          // exit the loop when rows = 0


*/

There are slicker (optimized/generic) ways to solve this, but the point is breaking down the problem and deriving code.

Best,
Dan