java - Building a pyramid and outputting the first line -

based on code below trying print out pyramid using input of rows looks this:

      *      *o*     *o*o* 

but arbitrary amount of rows. lines correctly cant figure out how first star correctly line up. outputs rows being 5:

              *             *o*          *o *o *o*       *o *o *o *o *o*    *o *o *o *o *o *o *o* *o *o *o *o *o *o *o *o *o* 

my code :

system.out.println("please enter number of rows: ");                     int row = scan.nextint();//takes in number of rows                      in=scan.nextline(); //gets rid of error .nextint();                                         string s="*";                     string pat="o";                     if(row>1){//this run through if number of rows entered greater 1                          (int =0; <= row; i++) {//this loop used build pyramid pattern                             // spacing                            (int j = 1; j <= row - i; j++){                                              system.out.print("   ");                                   }                              // left half of pyramid                                        (int k = i; k >= 1; k--){                                 if(k==0){                                      system.out.println(s);                                 }else{                                 system.out.print((k >= row+1) ? + k: " "+s + pat);                                 }                             }                             // corresponding right half of pyramid                             (int k = 2; k <= i; k++) {                                                                   system.out.print((k >= row+1) ? +k :  " "+ s + pat);                             }                             // next line                             system.out.println("*");                             }                      }else{                         system.out.println(s);                     } 

what row? it's 0 or more spaces followed * followed n repeats of o* n=0,1,2,... advance next line.

translate java, ignoring spaces now:

static void printrowvisiblepart(int n) {   system.out.print("*");   (int = 0; < n; i++) {     system.out.print("o*");   }   system.out.println();   } 

just fun, let's use print out visible part of pyramid of height k:

public class pyramidprinter {    public static void main(string[] args) {     int k = integer.parseint(args[0]);     (int n = 0; n < k; n++) {       printrowvisiblepart(n);     }   }    private static void printrowvisiblepart(int n) {     system.out.print("*");     (int = 0; < n; i++) {       system.out.print("o*");     }     system.out.println();     } } 

we get:

* *o* *o*o* *o*o*o* *o*o*o*o* 

this close. need spaces @ start of each line.

how many? start writing little method print them:

static void printspaces(int n) {   (int = 0; < n; i++) {     system.out.print(' ');   } } 

there fancier ways, fine.

now work backward. last row have n = k-1 k read user. know in row need 0 spaces. inspecting picture, note each row has 1 more space successor. row zero, then, need k-1 spaces, counting down each successive row 0 @ row k-1. in row n, need k - 1 - n spaces. change main bit print these spaces before each visible part of line.

  public static void main(string[] args) {     int k = integer.parseint(args[0]);     (int n = 0; n < k; n++) {       printspaces(k - 1 - n); // k-1 @ n=0 , 0 @ n=k-1!       printrowvisiblepart(n);     }   }