[leetcode刷题系列]String to Integer (atoi)

没啥好说的额

class Solution {public:    int atoi(const char *str) {        // Start typing your C/C++ solution below        // DO NOT write int main() function        while(*str != 0){            if(*str == ' ')                ++str;            else                break;        }        bool neg = false;        if(*str == '-')            neg = true, ++ str;        else if(*str == '+')            ++str;        if(*str == 0)            return 0;        long long now = 0;        for(;*str != 0; ++ str){            if(*str >= '0' && *str <= '9')                now = now * 10 + *str - '0';            else                 break;            if(now > INT_MAX)                break;        }        if(now > INT_MAX){            if(neg)                return INT_MIN;            else                return INT_MAX;        }        if(neg)            return -now;        return now;    }};