LeetCode 8. String to Integer (atoi)

题目：https://leetcode.com/problems/string-to-integer-atoi/

Implement atoi to convert a string to an integer.

 

思路：

　　把情况搞清楚就好了。

 

代码：C++：

int myAtoi(string str) {//这个代码思路比较乱
        int solve = 0;
        int coe = 1;
        bool find_sign = false;
        bool find_num = false;
        
        for (int i = 0; i < str.length(); i++) {
            if (isspace(str[i])){
                if (find_num || find_sign)
                    break;
                continue;
            }
            
            if (str[i] == '+'){
                if (find_sign)
                    return 0;
                find_sign = true;
                continue;
            }
            else if (str[i] == '-'){
                if (find_sign)
                    return 0;
                find_sign = true;
                coe = -1;
                continue;
            }
            
            if (isdigit(str[i])){
                find_sign = true;
                find_num = true;
                int temp = 10 * solve + (str[i] - '0');
                if (temp / 10 != solve)
                    return coe == 1 ? INT_MAX : INT_MIN;
                solve = temp;
                continue;
            }
            
            break;//meet other ASCII code
        }
        solve *= coe;
        return solve;
    }