Question

用java编写金字塔型的杨辉三角形程序

不能规定输入的行数，想输几行就输几行的

Answer 1

import java.util.*;
class tt
{
public static void main(String[]args)
{
    Scanner sc=new Scanner(System.in);
    int n=sc.nextInt();
int[][] a=new int[n][n];
int i=0,j=0;
for(i=0;i<n;i++)
{
for(j=n;j>=i;j--)
System.out.print("\t");
for(j=0;j<=i;j++)
{
if(i==j||j==0)
a[i][j]=1;
else
a[i][j]=a[i-1][j]+a[i-1][j-1];
System.out.print(a[i][j]+"\t\t");
if(i==j)
System.out.println();
}
}
}
}

Answer 2

public class 杨辉三角 {
public static void main (String args[])
{
final int maxline=10;
int yanghui [][]=new int [maxline][];
for(int i=0;i<yanghui.length;i++)
yanghui[i]=new int [i+1];
yanghui[0][0]=1;

for(int i=1;i<yanghui.length;i++)
{
yanghui[i][0]=1;
yanghui[i][yanghui[i].length-1]=1;
for(int j=1;j<yanghui[i-1].length;j++)
{yanghui[i][j]=yanghui[i-1][j-1]+yanghui[i-1][j];}

}
for(int i=0;i<yanghui.length;i++)
{ for(int k=yanghui.length-i;k>0;k--)
System.out.print(" ");
for(int j=0;j<yanghui[i].length;j++)
System.out.print(yanghui[i][j]+" ");
System.out.println();
}
}

}

Answer 3

public class Sxf040402
{public static void main(String args[])
{
final int ROW=5;
int a[][]=new int[ROW+1][];
for(int i=0;i<=ROW;i++)
{
a[i]=new int[i+1]; //指定每行的列数

}
yanghui(a,ROW);
}

static void yanghui(int a[][],int ROW)
{

for(int i=0;i<=ROW;i++)
for(int j=0;j<=a[i].length-1;j++)
{
if(i==0||j==0||j==a[i].length-1)
a[i][j]=1;
else a[i][j]=a[i-1][j-1]+a[i-1][j];

}
for(int i=0;i<=ROW;i++)
{
for(int j=0;j<=a[i].length-1;j++)
System.out.print(a[i][j]+"\t");
System.out.println();
}

}
}

Answer 4

可以使用scanner语句，让用户自定义行数（line的值）