Question

杨辉三角用java怎么编写代码???

Answer 1

package 大溶合;

/*
* @author qingsongwang
* @杨辉三角,标准的for实现..
*/

class yanghuisanjiao
{
public static void main(String args[]){
final int MAX=10;
int mat[][]=new int[MAX][];
int i=0,j,n;
n=MAX;

for(i=0;i<n;i++)
{
mat[i]=new int[i+1];
mat[i][0]=1;
mat[i][i]=1;
for(j=1;j<i;j++)
mat[i][j]=mat[i-1][j-1]+mat[i-1][j];
}
for(i=0;i<n;i++)
{
for(j=0;j<n-1;j++)
System.out.print(" ");
for(j=0;j<=i;j++)
System.out.print(" "+mat[i][j]);
System.out.println();
}
}
}

执行的效果如下......

Answer 2

public class F{
public static void main(String args[]){
int[][] arr=new int[10][10];
arr[0][0]=1;
arr[1][0]=1;
arr[1][1]=1;
for (int i = 2; i<arr.length; i++){
for (int j = 0; j<arr.length; j++){
if((i==j)||(j==0)){
arr[i][j]=1;
}else{
arr[i][j]=arr[i-1][j-1]+arr[i-1][j];
}
}
}
for (int i = 0; i<arr.length; i++){
for (int j = 0; j<arr.length; j++){
if(arr[i][j]!=0){
System.out.print (arr[i][j]+"\t");
}
}
System.out.println ();
}
}

}

Answer 3

int[] triangle=null;
int[] tmp=null;
for (int i=0;i<10;i++){
if(i==0){
tmp = new int[1];
tmp[0]=1;
} else if (i==1){
tmp = new int[3];
tmp[0] = 1;
tmp[1] = 2;
tmp[2] = 1;
}
else {
tmp=new int [i+2];
tmp[0]=1;
for(int j=1;j<i+1;j++){
tmp[j]=triangle[j-1]+triangle[j];
}
tmp[tmp.length-1]=1;
}
triangle=tmp;
for(int j=0;j<triangle.length;j++){
System.out.print(tmp[j]);
System.out.print(" ");
}
System.out.println();
}