class Solution {
public:
    int strToInt(string str) {
        int k = 0;
        while (k < str.size() && str[k] == ' ') k ++ ;
        long long res = 0;
        int minus = 1;
        if (k < str.size())
        {
            if (str[k] == '-') minus = -1, k ++ ;
            else if (str[k] == '+') k ++ ;
        }
        while (k < str.size() && str[k] >= '0' && str[k] <= '9')
        {
            res = res * 10 + str[k] - '0';
            if (res > 1e11) break;
            k ++ ;
        }
        res *= minus;
        if (res > INT_MAX) res = INT_MAX;
        if (res < INT_MIN) res = INT_MIN;
        return res;
    }
};