[蓝桥] 基础练习 十六进制转十进制

 1 import java.util.Scanner;
 2 
 3 public class Main {
 4     public static void main(String[] stgs) {
 5         Scanner scanner = new Scanner(System.in);
 6         String str = scanner.nextLine();
 7         char[] arr = str.toCharArray();
 8         int len = arr.length;
 9         long sum = 0;
10         for (int i = 0; i < len; i++) {
11             if ((int) arr[i] - 48 > 9) {
12                 if (arr[i] == ‘A‘)
13                     sum += 10 * Math.pow(16, len - i - 1);
14                 else if (arr[i] == ‘B‘)
15                     sum += 11 * Math.pow(16, len - i - 1);
16                 else if (arr[i] == ‘C‘)
17                     sum += 12 * Math.pow(16, len - i - 1);
18                 else if (arr[i] == ‘D‘)
19                     sum += 13 * Math.pow(16, len - i - 1);
20                 else if (arr[i] == ‘E‘)
21                     sum += 14 * Math.pow(16, len - i - 1);
22                 else if (arr[i] == ‘F‘)
23                     sum += 15 * Math.pow(16, len - i - 1);
24             } else {
25                 sum += ((int) arr[i] - 48) * Math.pow(16, len - i - 1);
26             }
27         }
28         System.out.println(sum);
29     }
30 }