16 – 十进制转二进制

Time Limit: 1000   Memory Limit: 65535
Submit: 802  Solved: 447

Description

编写代码，要求：输入参数是一个正整数，输出该整数所对应的二进制数对应的字符串。

Input

正整数

Output

输入的正整数对应的二进制字符串“1001”

Sample Input

9

Sample Output

1001

方法一：用数组模拟栈

package 十进制转二进制;
import java.util.Scanner;
//import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		int n,k=0;
		int []a = new int [100000];
		Scanner scanner = new Scanner(System.in);
		n = scanner.nextInt();
		if(n==0)
			System.out.println(0);
		else
		{
			while(n!=0)
			{
				a[k++] = n%2;
				n/=2;
			}
			for(int i = k - 1;i >= 0; i--)
			{
				System.out.print(a[i]);
			}
			System.out.println();
		}
	}

}

方法二：利用java API函数

package 十进制转二进制;
import java.util.Scanner;
//import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		int n;
		Scanner scanner = new Scanner(System.in);
		n = scanner.nextInt();
		System.out.println(Integer.toBinaryString(n));
	}

}