[leetcode] 1023. Camelcase Matching

Description

A query word matches a given pattern if we can insert lowercase letters to the pattern word so that it equals the query. (We may insert each character at any position, and may insert 0 characters.)

Given a list of queries, and a pattern, return an answer list of booleans, where answer[i] is true if and only if queries[i] matches the pattern.

Example 1:

Input: queries = ["FooBar","FooBarTest","FootBall","FrameBuffer","ForceFeedBack"], pattern = "FB"
Output: [true,false,true,true,false]
Explanation: 
"FooBar" can be generated like this "F" + "oo" + "B" + "ar".
"FootBall" can be generated like this "F" + "oot" + "B" + "all".
"FrameBuffer" can be generated like this "F" + "rame" + "B" + "uffer".

Example 2:

Input: queries = ["FooBar","FooBarTest","FootBall","FrameBuffer","ForceFeedBack"], pattern = "FoBa"
Output: [true,false,true,false,false]
Explanation: 
"FooBar" can be generated like this "Fo" + "o" + "Ba" + "r".
"FootBall" can be generated like this "Fo" + "ot" + "Ba" + "ll".

Example 3:

Input: queries = ["FooBar","FooBarTest","FootBall","FrameBuffer","ForceFeedBack"], pattern = "FoBaT"
Output: [false,true,false,false,false]
Explanation: 
"FooBarTest" can be generated like this "Fo" + "o" + "Ba" + "r" + "T" + "est".

Note:

1. 1 <= queries.length <= 100
2. 1 <= queries[i].length <= 100
3. 1 <= pattern.length <= 100
4. All strings consists only of lower and upper case English letters.

分析

題目的意思是：給定一個字串陣列queries，和模板pattern，文queries裡面的query能夠匹配上pattern。這道題我看了一下提示，要用動態規劃啥的，頓時傻了眼。後面才發現用雙指標法也能搞定，看來我還需要沉澱。思想很簡單，遍歷queries，然後對每個字元用雙指標和pattern進行匹配。

程式碼

class Solution:
    def match(self,p,q):
        n=len(q)
        j=0
        for i in range(n):
            if(j<len(p) and p[j]==q[i]):
                j+=1
            elif(q[i].isupper()):
                return False
        return j==len(p)
    
    def camelMatch(self, queries: List[str], pattern: str) -> List[bool]:
        res=[]
        for query in queries:
            t=self.match(pattern,query)
            res.append(t)
        return res

參考文獻

[LeetCode] Python - Two Pointer - Memory usage less than 100%