java版杨辉三角算法

package firstclass;

public class test {
public static void main(String[] args) {
int a[][] = new int[5][5];
a[0][0] = 1;
a[1][0] = 1;
a[1][1] = 1;
for (int i = 2; i < 5; i++) {
for (int j = 0; j < i + 1; j++) {
a[i][0] = 1;
a[i][i] = 1;
if (j >= 1) {
a[i][j] = a[i - 1][j] + a[i - 1][j - 1];
}

}

}
StringBuffer sb = new StringBuffer();
for (int b = 0; b < 5; b++) {
sb.append("\n");
for (int c = 0; c < b + 1; c++) {
sb.append(" " + a[b][c]);
}

}
System.out.println(sb);

}