8. String to Integer (atoi)

题目链接：https://leetcode.com/problems/string-to-integer-atoi/?tab=Description

Description

Implement atoi to convert a string to an integer.

Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the possible input cases.

Notes: It is intended for this problem to be specified vaguely (ie, no given input specs). You are responsible to gather all the input requirements up front.

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 Math String

My Answer

class Solution {public:    int myAtoi(string str) {        long res = 0;        int flag = 1;        for(int i = 0; i<str.size(); i++)        {            if(' ' == str[i])            {                continue;            }            else             {                if('-' == str[i] || '+' == str[i])                {                flag = ('-' == str[i++]) ? -1 : 1;                }                while('0'<= str[i] && str[i] <= '9')                {                    res = res * 10 + (str[i++] - '0');                    if(res * flag > INT_MAX) return INT_MAX;                    if(res * flag < INT_MIN) return INT_MIN;                }                return res * flag;            }        }        return 0;    }};

Submission Details

1047 / 1047 test cases passed.

Status: 

Accepted

Runtime: 22 ms

Submitted: 3 minutes ago