蓝桥杯试题练习1

import java.util.Scanner;
public class demo {
 
	//用来存储信用卡号
	static String num;

	static char num2[] = new char[16];
	static int sum_odd;	//用来存储奇数位和
	static int sum_even;   //用来存储偶数位和
	static int sum; //用来存储和
	static Scanner scanner = new Scanner(System.in);
	
	//获得信用卡号
	static char[] get_num(String num){
		//int length_num = num.length();
		System.out.println("请输入16位信用卡号：");
	    num = scanner.next();
		
	    num2 = num.toCharArray();
	    return num2;
	}
	static //获得奇数位和
	int getSum_odd(char num[]){
		
		for(int i=15;i>0;i-=2){
			sum_odd += Integer.parseInt(String.valueOf(num[i]));
		}
		return sum_odd;
	}
	static //获得偶数位和
	int getSum_even(char[] num){
		for(int i=14;i>=0;i-=2){
			int a=Integer.parseInt(String.valueOf(num[i]));
		    if((a*=2)>=10)
		    	a-=9;
			sum_even +=a;		
		}
		return sum_even;
	}
	public static void main(String[] args) {
		get_num(num);
		sum = getSum_odd(num2) + getSum_even(num2);
		if(sum%10==0){
			System.out.println("成功！");
		}else{
			
			System.out.println("失败！");
		}
	}
}