十六进制转十进制

import java.util.Scanner;
public class HexToDecimal {

public static void main(String[] args){
Scanner sc = new Scanner(System.in);
String hex = sc.next();
System.out.println(hextoDecimal(hex));
}

public static long hextoDecimal(String hex){
long decimal = 0;
for(int i=0; i<hex.length(); i++){
char hexChar = hex.charAt(i);
decimal = decimal * 16 + toDecimal(hexChar);
}
return decimal;
}

public static long toDecimal(char ch){
if(ch >= 'A' && ch <= 'F')
return 10 + ch - 'A';
else
return ch - '0';
}
}