编写程序,打印如下的杨辉三角形：

public static void main(String[] args) {textYH yang = new textYH();yang。printYanghuiTriangle(5);}public void printYanghuiTriangle(int lines) {if(lines < 1) {throw new IllegalArgumentException("lines must be great than 0。");}if(lines > 30) {throw new IllegalArgumentException("lines is too big。");}int[] line = new int[lines];int maxLen = getMaxLen(lines);for(int i = 0; i < lines; i++) {line[0] = line[i] = 1;for(int j = 1,k = i / 2,pre = line[0]; j 0 start :1L;while(num > start) {result *= num--;}return result;}private int getLength(long num) {int len = 0;while(num > 0L) {num /= 10L;len++;}return len;}private void printLine(int[] yanghui,int line,int width) {printSpaces((yanghui。length - line) * width);for(int i = 0; i < line; i++) {if(i > 0) {printSpaces(width);}printSpaces(width - getLength(yanghui[i]));System。out。print(yanghui[i]);}System。out。println();if(width > 1) {System。out。println();}}private void printSpaces(int spaceCount) {for(int i = 0; i < spaceCount; i++) {System。out。print(" ");}}