Problem's Link
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Mean:
给你一个字符串，让你将其转换为数字.
analyse:
注意细节，坑点有点多.
Time complexity: O(N)
view code
class Solution
{
public:
int myAtoi(string str)
{
int ret = 0, sign = 1, i = str.find_first_not_of(' '), base = INT_MAX / 10;
if (str[i] == '+' || str[i] == '-') sign = str[i++] == '+' ?: -1;
while (isdigit(str[i]))
{
if (ret > base || (ret == base && str[i] - '0' > 7))
return sign > 0 ? INT_MAX : INT_MIN;
ret = 10 * ret + (str[i++] - '0');
}
return sign * ret;
}
};
{
public:
int myAtoi(string str)
{
int ret = 0, sign = 1, i = str.find_first_not_of(' '), base = INT_MAX / 10;
if (str[i] == '+' || str[i] == '-') sign = str[i++] == '+' ?: -1;
while (isdigit(str[i]))
{
if (ret > base || (ret == base && str[i] - '0' > 7))
return sign > 0 ? INT_MAX : INT_MIN;
ret = 10 * ret + (str[i++] - '0');
}
return sign * ret;
}
};