class Solution {
public:
    int strToInt(string str) {
        int k = 0;
        while (k < str.size() && str[k] == ' ') k ++ ;

        long long number = 0;
        bool is_f = false;
        if (str[k] == '+') k ++ ;
        else if(str[k] == '-')
        {
            is_f = true;
            k ++ ;
        }

        while (k < str.size() && str[k] >= '0' && str[k] <= '9')
        {
            number = number * 10 + str[k] - '0';
            k ++ ;
        }

        if (is_f) number *= -1;
        if (number > INT_MAX) number = INT_MAX;
        else if (number < INT_MIN) number = INT_MIN;
        return (int)number;
    }
};