zuoye_4.java

杨辉三角实现

import java.io.*;
public class zuoye_4
{ 
    public static void main(String args[]) 
    {
        try
        {
	        System.out.print("请输入杨辉三角的规模：");
            BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
            int n=Integer.parseInt(stdin.readLine()); 
            int a[][]=new int[n][]; 
            int i,j;
            for(i=0;i<n;i++) 
            { 
                a[i]=new int[i+1]; 
                for(j=0;j<i+1;j++) 
                { 
                    if(j==0||j==i)
                    	a[i][j]=1; 
                    else 
                        a[i][j]=a[i-1][j-1]+a[i-1][j]; 
                } 
           } 
           System.out.println("行杨辉三角为：");
           for (i=0;i<n;i++) 
           { 
               for(j=0;j<n-i;j++) 
               System.out.print("  "); 
               for(j=0;j<i+1;j++) 
               System.out.print(a[i][j]+"   "); 
               System.out.print("\n"); 
          }
        
      }
     catch(IOException e)
      {
      		System.err.println("IOException");
      }

  }
}