以帕斯卡三角形代碼重複值

Question

我在同一行中多次打印相同的值時遇到問題。 printInt方法是我用來創建打印值之間的間距，並可能是問題的原因。 nChoosek方法使用二項式方程來計算放置在行中的值。打印方法是使用所有輔助方法的主要打印方法。

public class P2ascalsTriangle extends PascalsTriangleBase{ 
    protected int nChooseK(int n, int k) { 
    int x= fac(n); 
    int y= fac(k) * fac(n-k); 
    int fac_n_y = (int) (x/y); 
    return fac_n_y; 
    } 
    protected void printInt(int n){ 
     int[] c= new int[n]; 
     for (int i=0; i<c.length; i++){ 
     System.out.printf("%5d",n); 
     } 
    } 
    private static int fac(int num){ 
    int product = 1; 
    for (int i=1; i<=num; i++){ 
     product*=i; 
    } 
    return product; 
    } 
    protected boolean heightOutOfRange(int height) { 
    if(height<0); 
     return false; 
    } 
    public static void main(String[] args){ 

    P2ascalsTriangle pascal = new P2ascalsTriangle(); 

    pascal.printTriangle(0); 
    pascal.printTriangle(10); 
    pascal.printTriangle(5); 
    pascal.printTriangle(2); 
    } 
} 


public class PascalsTriangleBase { 

    /** 
    * This field controls the line spacing of the output triangle. 
    */ 
    protected boolean doubleSpace; 

    /** 
    * Simple constructor to set the value for the field. 
    */ 
    public PascalsTriangleBase() { 
     doubleSpace = false; 
    } 

    /** 
    * This method is the primary printing method for the triangle. 
    * Override this method to control the spacing between values in 
    * the output triangle. 
    * @param n The value to be printed 
    */ 
    protected void printInt(int n) { 
     System.out.print(n); 
    } 

    /** 
    * This method calculates the binomial coefficient, n choose k. These 
    * values are used to construct Pascal's Triangle. They are called 
    * <i>binomial coefficients</i> because "n choose k" is the value of 
    * the coefficient of the x<sup>k</sup> term in the expansion of 
    * (1 + x)<sup>n</sup>. 
    * <p>For this assignment, it should use the factorial algorithm; that is 
    * the return value should be calculated as n!/(k! (n-k)!). 
    * @param n The power for the binomial expansion 
    * @param k The order of the term in the binomial expansion 
    * @return The coefficient of the k<sup>th</sup> term. 
    */ 
    protected int nChooseK(int n, int k) { 
     return k; 
    } 

    /** 
    * The is a special method that is used to print the first value in each 
    * row of Pascal's triangle. The amount of "indent" for the line can be 
    * determined by the parameter values. 
    * @param row The number of the row being printed 
    * @param height The height of the completed triangle 
    */ 
    protected void printOne(int row, int height) { 
     printInt(1); 
    } 

    /** 
    * A simple input validation routine to see if the height is ok. 
    * @param height The requested height for the triangle 
    * @return True if the requested height is out of range 
    */ 
    protected boolean heightOutOfRange(int height) { 
     return false; 
    } 

    /** 
    * The core method for this assignment. It prints out the triangle, 
    * using the helper methods defined above. This method is marked with 
    * the <b>final</b> keyword. This means that this method cannot be 
    * overridden in a subclass. Notice that all of the helper methods 
    * are not declared <b>final</b>, so they are all available for 
    * overriding. 
    * @param height The requested height for the triangle to be printed. 
    */ 
    public final void printTriangle(int height) { 
     System.out.println("Pascal\'s Triangle of height " + height); 
     if(heightOutOfRange(height)) { 
      System.out.println("Height is out of range. Cannot print Pascal's triangle."); 
      return; 
     } 
     System.out.println(); 
     for(int row = 0; row < height + 1; row ++) { 
      printOne(row, height); 
      for(int col = 1; col < row + 1; col ++) { 
       printInt(nChooseK(row, col)); 
      } 
      System.out.println(); 
      if(doubleSpace) { 
       System.out.println(); 
      } 
     } 
     System.out.println(); 
     System.out.println(); 
    } 

} 

Answer 1

我有下面的代碼，但我的麻煩剛剛寫了打印楊輝三角爲你一個方法：

public static void printPT(final int n) { 
    ArrayList<Integer> layer = new ArrayList<>(); 
    layer.add(1); 
    for (int i = 0; i < n; i++) { 
     ArrayList<Integer> newLayer = new ArrayList<>(); 
     newLayer.add(1); 
     for (int j = 0; j < i; j++) { 
      newLayer.add(layer.get(j) + layer.get(j + 1)); 
     } 
     newLayer.add(1); 
     for (int num : layer) { 
      System.out.print(num + " "); 
     } 
     layer = newLayer; 
     System.out.println(); 
    } 
}