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

        int minus = 1;
        if(str[k] == '-') minus = -1, k++;
        else if(str[k] == '+') k++;

        long res = 0;
        while(k < str.size() && str[k] >= '0' && str[k] <= '9')
        {
            res = res * 10 + minus * (str[k] - '0');
            if(res >= INT_MAX) return INT_MAX;
            if(res <= INT_MIN) return INT_MIN;
            k++;
        }

        return res;
    }
};