leetcode --8. String to Integer (atoi)

题目：https://leetcode.com/problems/string-to-integer-atoi/description/

代码：

class Solution {public:    int myAtoi(string str) {        if(str == "") return 0;        int pos = 0,temp=1;        double res = 0;        while(str[pos]==' '){            pos++;        }        if(str[pos]=='+'){            temp = 1;            pos++;        }else if(str[pos]=='-'){            temp = -1;            pos++;        }        while(pos!=str.size()&&'0'<= str[pos] && str[pos] <= '9'){               res = res*10+(str[pos++]-'0');                         }        if(res*temp>=INT_MAX){            return INT_MAX;        }else if(res*temp<=INT_MIN){            return INT_MIN;        }else{            return res*temp;        }    }};