leetcode个人题解——#8 string to integer

第八题

class Solution {
public:
    int myAtoi(string str) {
        int i = ;
        long sum = ;
        int sign = ;
        while(str[i] == ' ')i++;
        if (str[i] == '-'|| str[i] == '+')
        {
            if(str[i] == '-') sign = -;
            i++;
        }
        while(str[i]<='' && str[i]>='')
        {
            if(sum>=INT_MAX) break;
            sum = sum *  + str[i++] - '';
        }
        sum*=sign;
        if(sum>=INT_MAX)return INT_MAX;
        if(sum<=INT_MIN)return INT_MIN;
        return sum;
    }
};