题解 | #进制转换#

public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
    while (in.hasNext()) {
        String string = in.nextLine();
        js(string);
    }
}
static void js(String str) {
    String string = str.replace("0x", "");
    String[] str16 = string.split("");
    int c = 0;
    for (int i = str16.length - 1,j = 0; i >= 0; i--,j++) {
        switch (str16[i]) {
            case "A":
                c+= 10*(Math.pow(16,j));
                break;
            case "B":
                c+= 11*(Math.pow(16,j));
                break;
            case "C":
                c+= 12*(Math.pow(16,j));
                break;
            case "D":
                c+= 13*(Math.pow(16,j));
                break;
            case "E":
                c+= 14*(Math.pow(16,j));
                break;
            case "F":
                c+= 15*(Math.pow(16,j));
                break;
            default:
                c+= Integer.parseInt(str16[i])*(Math.pow(16,j));
        }
    }
    System.out.println(c);
}