The recursive program will result in TLE like this:

class Solution {
public:
bool isMatch(const char *s, const char *p) {
// IMPORTANT: Please reset any member data you declared, as
// the same Solution instance will be reused for each test case.
if (*s == *p && *s == '\0')
return true;
if (*p == '?' || *s == *p)
return isMatch(s + 1, p + 1);
else if (*p == '*') {
int i;
for (i = 0; *(s + i); ++i)
if (isMatch(s + i, p + 1))
return true;
if (isMatch(s + i, p + 1))
return true; return false;
}
else if (*p != *s)
return false;
}
};

So it's necessary to write an non-recursive program. The key point is to match the '*' in p string. We could attempt to match '*' with 0...n characters in s, i.e.,
the character after '*' maybe match any position in s regardless a series of characters in s. Take notice that
consecutive '*'s are equal to one '*'. Based on that, a lengthy code is written as :

class Solution {
public:
bool isMatch(const char *s, const char *p) {
// IMPORTANT: Please reset any member data you declared, as
// the same Solution instance will be reused for each test case.
bool star = false, staremerge = false;
const char *str = s, *ptr = p, *ss = s, *pp = p;
for (str = ss, ptr = pp; *str && *ptr || *str == '\0' && *ptr == '*'; ++str, ++ptr) {
if (*ptr == '*') {
star = staremerge = true;
while (*ptr == '*')
++ptr;
if (*ptr == '\0')
return true;
ss = str;
pp = ptr;
--str;
--ptr;
}
else {
if (!star) {
if( !staremerge ) {
if (*str != *ptr && *ptr != '?' ||*(ptr + 1) == '\0' && *(str + 1) != '\0')
return false;
}
else {
if (*str != *ptr && *ptr != '?' ||*(ptr + 1) == '\0' && *(str + 1) != '\0') {
str = ss++;
ptr = pp - 1;
star = true;
} }
}
else if (star) {
if ( *str != *ptr && *ptr != '?') {
ss = str + 1;
--ptr;
}
else {
star = false;
if (*(ptr + 1) == '\0' && *(str + 1) != '\0') {
str = ss++;
ptr = pp - 1;
star = true;
}
}
}
}
}
if (*str == *ptr && *str == '\0')
return true;
else
return false;
}
};

Some suggestions about this code:

1. There is no need to refresh the status of star, staremerge. Only one star is enough, because the character(for example, 'a') always needs to match some 'a' in s. Matching the former 'a' is better than the latter 'a' in s as is illustrated in the figure. I.e., there is no need to record the matching range for every '*', the latest '*' has the largest range of choice.

2. sbegin is refreshed when mismatch occurs and pbegin is refreshed when meeting new '*';

3. Focusing on s is better than handling the two strings at the same time.

So the final concise code is like:

class Solution {
public:
bool isMatch(const char *s, const char *p) {
// IMPORTANT: Please reset any member data you declared, as
// the same Solution instance will be reused for each test case.
const char *sbegin = s, *pbegin = p, *str = s, *ptr = p;
bool star = false;
for (str = s, ptr = p; *str || *ptr == '*'; ++str, ++ptr) {
if (*ptr == '*') {
star = true;
while (*ptr == '*')
++ptr;
if (*ptr == '\0')
return true;
pbegin = ptr--;
sbegin = str--;
}
else if (*str != *ptr && *ptr != '?'){
if (!star)
return false;
str = sbegin++;
ptr = pbegin - 1;
}
}
return *ptr == '\0';
}
};

leetcode Wildcard Matching greedy algrithm的更多相关文章

  1. LeetCode: Wildcard Matching 解题报告

    Wildcard MatchingImplement wildcard pattern matching with support for '?' and '*'. '?' Matches any s ...

  2. [LeetCode] Wildcard Matching 题解

    6. Wildcard Matching 题目 Implement wildcard pattern matching with support for '?' and '*'. '?' Matche ...

  3. [LeetCode] Wildcard Matching 外卡匹配

    Implement wildcard pattern matching with support for '?' and '*'. '?' Matches any single character. ...

  4. [LeetCode] Wildcard Matching 字符串匹配,kmp,回溯,dp

    Implement wildcard pattern matching with support for '?' and '*'. '?' Matches any single character. ...

  5. [Leetcode] Wildcard Matching

    Implement wildcard pattern matching with support for '?' and '*'. '?' Matches any single character. ...

  6. [leetcode]Wildcard Matching @ Python

    原题地址:https://oj.leetcode.com/problems/wildcard-matching/ 题意: Implement wildcard pattern matching wit ...

  7. [Leetcode] Wildcard matching 通配符匹配

    Implement wildcard pattern matching with support for'?'and'*'. '?' Matches any single character. '*' ...

  8. [LeetCode]Wildcard Matching 通配符匹配(贪心)

    一開始採用递归写.TLE. class Solution { public: bool flag; int n,m; void dfs(int id0,const char *s,int id1,co ...

  9. [Leetcode][Python]44:Wildcard Matching

    # -*- coding: utf8 -*-'''__author__ = 'dabay.wang@gmail.com' 44:Wildcard Matchinghttps://oj.leetcode ...

随机推荐

  1. codecombat js

    #1 // Move to the gem. // Don't touch the walls! // Type your code below. this.moveRight(); this.mov ...

  2. python循环与判断

    学习一门新的语言最重要的就是练习. 一.脚本需求: 编写登陆接口 输入用户名密码 认证成功后显示欢迎信息 输错三次后锁定 二.脚本流程图: 写代码之前画个流程图总是好的,可以让你理清思路,避免写着写着 ...

  3. Python—对Excel进行读写操作

    学习Python的过程中,我们会遇到Excel的读写问题.通过搜索得知,我们可以使用xlwt module将数据写入Excel表格,使用xlrd module从Excel读取数据.下面介绍如何实现使用 ...

  4. .Net 中DataSet和DataTable的 区别与联系

    1.简要说明二者关系 在我们编写代码的时候从数据库里取出数据,填充到dataset里,再根据表的名字,实例化到 datatable 中.其实使用 dataset 相当于所使用数据库中数据的副本,保存在 ...

  5. 强烈推荐:Android史上最强大的自定义任务软件Tasker

    强烈推荐:Android史上最强大的自定义任务软件Taskerhttp://bbs.mumayi.com/thread-28387-1-1.html(出处: 木蚂蚁手机乐园) Android上的Tas ...

  6. Jenkins搭建.NET自动编译测试与发布环境

    本文地址: http://blog.csdn.net/wangjia184/article/details/18365553 操作系统Windows, 确保需要的.NET Framework已经安装 ...

  7. JDBC 连Sql Server 接数据库--The TCP/IP connection to the host localhost, port 1433 has failed

    原文:https://blog.csdn.net/qq_39241986/article/details/80848855 这样的错误,你有遇到过吗? The TCP/IP connection to ...

  8. android 4.4删除短信

    android 4.4之后非默认的短信应用已经没有办法删除短信了.像以前那样用如下方法是不会没法删除短信的(即使在xml中配置了短信的读写权限),同时也不会有报错或其他提示. public void ...

  9. ubuntu下C++和C编程

      一.anjuta Anjuta DevStudio 的官方地址:http://anjuta.sourceforge.net/Anjuta是一个C/C++ IDE,它最大的特色是灵活,同时打开多个文 ...

  10. Log4j输出格式控制

    参数说明例子 %c 列出logger名字空间的全称,如果加上{<层数>}表示列出从最内层算起的指定层数的名字空间 log4j配置文件参数举例 输出显示媒介 假设当前logger名字空间是& ...