程序员面试金典 - 面试题 01.01. 判定字符是否唯一（位运算，牛）

示例 1：
输入: s = "leetcode"
输出: false 

示例 2：
输入: s = "abc"
输出: true

限制：
0 <= len(s) <= 100
如果你不使用额外的数据结构，会很加分。

class Solution {
public:
    bool isUnique(string astr) {
        long long a = 0, b = 0, one = 1;
        for(auto& ch : astr)
        {
            if(ch < 64)
            {
                if((a&(one<<ch)^(one<<ch))!=0)
                    a ^= (one<<ch);
                else
                    return false;
            }
            else
            {
                if((b&(one<<(ch-64))^(one<<(ch-64)))!=0)
                    b ^= (one<<(ch-64));
                else
                    return false;
            }
        }
        return true;
    }
};

Line 16: Char 25: runtime error: shift exponent 51 is too large 
for 32-bit type 'int' (solution.cpp)

#include "stdio.h"
int main()
{
	printf("Int是%d位\n",sizeof(int)*8);
	printf("uInt是%d位\n",sizeof(unsigned int)*8);
	printf("Long是%d位\n",sizeof(long)*8);
	printf("uLong是%d位\n",sizeof(unsigned long)*8);
	printf("LL是%d位\n",sizeof(long long)*8);
	printf("uLL是%d位\n",sizeof(unsigned long long)*8);
}