08.字符串转换位整数

Posted 2022-09-18 baizhuang

题目：

 

 

 

 提交：

class Solution 
    public int myAtoi(String str) 
         str = str.trim();
        if (str == null || str.length() == 0) return 0;

        // + - 号
        char firstChar = str.charAt(0);
        int sign = 1;
        int start = 0;
        long res = 0;
        if (firstChar == ‘+‘) 
            sign = 1;
            start++;
         else if (firstChar == ‘-‘) 
            sign = -1;
            start++;
        

        for (int i = start; i < str.length(); i++) 
            if (!Character.isDigit(str.charAt(i))) 
                return (int) res * sign;
            
            res = res * 10 + str.charAt(i) - ‘0‘;
            if (sign == 1 && res > Integer.MAX_VALUE) return Integer.MAX_VALUE;
            if (sign == -1 && res > Integer.MAX_VALUE) return Integer.MIN_VALUE;
        
        return (int) res * sign;
    

评论:奇葩输入太多，只能参考别人的代码