算法题（三）：十六进制十进制间的相互转换

     //十六进制转成十进制
     public static void fun1(String str) {
		if(str==null || str.length()<2 || "0x".equals(str.substring(0, 1))) {
			return;
		}
		String nums = str.substring(2);
		System.out.println(nums);
		int result = 0;
		for(int i=0; i<nums.length(); i++) {
			if(nums.charAt(i) >='0' && nums.charAt(i)<='9') {
				int temp = nums.charAt(i) - '0';
				result = result*16+temp;
			}else if(nums.charAt(i)>='a' && nums.charAt(i)<='z') {
				int temp = nums.charAt(i) - 'a'+10;
				result = result*16+temp;
			}else if(nums.charAt(i)>='A' && nums.charAt(i)<='Z') {
				int temp = nums.charAt(i) - 'A'+10;
				result = result*16+temp;
			}
		}
		System.out.println(result);
	}
	//十进制转成十六进制
	public static void fun2(int number) {
		Stack<Integer> stack = new Stack<>();
		String res = "0x";
		while(number!=0) {
			stack.push(number%16);
			number = number/16;
		}
		while(!stack.isEmpty()) {
			res += stack.pop();
		}
		System.out.println(res);
	}