Question

java编写杨辉三角

Answer 1

import java.util.Scanner;

public class PascalTriangle {

public static void main(String[] args) {

System.out.print("Please input a digit for pascal triangle: ");

Scanner scanner = new Scanner(System.in);

final int num = scanner.nextInt();

int[][] ary = getPascalTriangle(num);

for(int[] item: ary){
for(int value: item){
System.out.print((value > 0? value: "") + " ");
}
System.out.println();
}

}

private static int[][] getPascalTriangle(final int num) {
int[][] ary = new int[num][num];

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

for(int i = 1; i < ary.length; i++){
for(int j = 1; j <= i; j++){
ary[i][j] = ary[i-1][j-1] + ary[i-1][j];
}
}
return ary;
}
}
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Please input a digit for pascal triangle: 7
1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1
1 6 15 20 15 6 1