8.txt

class Solution 
{
public:
    int myAtoi(string str)
    {
        if (str.empty()) return 0;
        long long base = 0 ; 
        int sign = 1;
        int i = 0;
        
       
        while(str[i] == ' ') i++;
        

         if(str[i] == '+' || str[i] == '-')//·­ÒëÕý¸ººÅ
        {
            sign = (str[i] == '-')? -1: 1;
            i++;
        }
        
        
        while(str[i] >= '0' && str[i] <= '9' && i < str.size())
        {
            int digit = str[i] - '0';
            base=base * 10 + digit;
            if ((sign == 1 && base > INT_MAX) ||(sign == -1 && -base < INT_MIN))
            {
                 return (sign == 1)? INT_MAX:INT_MIN;
                
            }
               
            
            i++;
        }
            
        return base*sign;
    }
    
};