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50 lines (42 loc) · 917 Bytes
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import java.util.Scanner;
public class Ch1_5
{
public static void main(String[] args)
{
System.out.print("请输入行数：");
Scanner scanner = new Scanner(System.in);
int num = scanner.nextInt();
int[][] ary = getTriangle(num);//得到杨辉三角
print(ary);//打印杨辉三角
}
//得到杨辉三角
private static int[][] getTriangle(int num)
{
int[][] ary = new int[num][num];//用二维数组存储
for(int i = 0; i < ary.length; i++)//竖边、斜边置1
{
ary[i][0] = 1;
ary[i][i] = 1;
}
for(int i = 1; i < ary.length; i++)
{
for(int j = 1; j <= i; j++)
{
//里面部分，等于当前位置的上方和左上角之和
ary[i][j] = ary[i-1][j-1] + ary[i-1][j];
}
}
return ary;
}
private static void print(int[][] ary)
{
for(int i=0;i<ary.length;i++)
{
for(int j=0;j<=i;j++)
{
System.out.printf(" %-3d", ary[i][j]);
}
System.out.println();
}
}
}