【leetcode with java】8 String to Integer (atoi)
来源:互联网 发布:济南整站优化方案 编辑:程序博客网 时间:2024/06/09 05:00
<pre name="code" class="plain">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.Update (2015-02-10):The signature of the C++ function had been updated. If you still see your function signature accepts a const char * argument, please click the reload button to reset your code definition.spoilers alert... click to show requirements for atoi.Requirements for atoi:The function first discards as many whitespace characters as necessary until the first non-whitespace character is found. Then, starting from this character, takes an optional initial plus or minus sign followed by as many numerical digits as possible, and interprets them as a numerical value.The string can contain additional characters after those that form the integral number, which are ignored and have no effect on the behavior of this function.If the first sequence of non-whitespace characters in str is not a valid integral number, or if no such sequence exists because either str is empty or it contains only whitespace characters, no conversion is performed.If no valid conversion could be performed, a zero value is returned. If the correct value is out of the range of representable values, INT_MAX (2147483647) or INT_MIN (-2147483648) is returned.Tags: Math String
【上码】
public class Solution {public int myAtoi(String str) {if(str == null || str.length()==0)return 0;int p,q, len=str.length();for(p=0; p<len; p++)if(str.charAt(p) != ' ')break;boolean negative = false;if(str.charAt(p) == '+')p++;else if(str.charAt(p) == '-'){negative = true;p++;}for(; p<len; p++)if(str.charAt(p) != '0')//去掉前导的0break;for(q=p; q<len; q++)if(!Character.isDigit(str.charAt(q)))break;if(q == p)//空串return 0;if(q-p > 10)if(negative)return Integer.MIN_VALUE;else return Integer.MAX_VALUE;String numstr = str.substring(p,q);//str[p][q-1]double ans = 0;//ans = Double.parseDouble(numstr);for(int i=0; i<numstr.length(); i++){ans = ans*10+(numstr.charAt(i)-'0');}if(negative)ans = -ans;if(ans>Integer.MAX_VALUE)ans = Integer.MAX_VALUE;else if(ans<Integer.MIN_VALUE)ans = Integer.MIN_VALUE;return new Double(ans).intValue();}}
0 0
- 【leetcode with java】8 String to Integer (atoi)
- [LeetCode Java] 8 String to Integer (atoi)
- [leetcode-8]String to Integer (atoi)(java)
- 【LeetCode with Python】 String to Integer (atoi)
- [Leetcode] String to Integer (atoi) (Java)
- LeetCode – String to Integer (atoi) (Java)
- 【Leetcode】String to Integer(atoi) in JAVA
- [LeetCode][Java] String to Integer (atoi)
- LeetCode : String to Integer (atoi) [java]
- Leetcode: 8. String to Integer (atoi)(JAVA)
- LeetCode(java)8. String to Integer (atoi)
- [LeetCode-Java]8. String to Integer (atoi)
- [LeetCode] 8. String to Integer (atoi) java
- leetcode String to Integer (atoi)(Java)
- String to Integer (atoi) leetcode java
- [leetcode]8. String to Integer (atoi)(Java)
- 【LeetCode】String to Integer (atoi)(java)
- LeetCode 8 String to Integer (atoi) (C,C++,Java,Python)
- Unity3D 优化总篇
- 局域网流量分析及工具
- Exploring Design Challenges in Getting Solid State Drives Closer to CPU
- 史上最简单的软件破解——5行脚本代码完美破解99%的过期软件
- Android学习笔记(10)——数据适配器ArrayAdapter和SimpleAdapter
- 【leetcode with java】8 String to Integer (atoi)
- 图像搜索算法
- Leetcode 75Sort Colors
- ARM Linux 设置时间
- PDF转Word神器—ABBYY FineReader,这个必须有!(图文)
- Android JNI 开发 Demo by NDK (native develop kit)
- 谷歌火狐浏览器用append()方法,不能实现ajax刷新问题
- 5+ App开发入门指南
- 奇葩的生命周期