Leetcode 1961. Check If String Is a Prefix of Array

Posted 2021-09-07 SnailTyan

文章作者：Tyan
博客：noahsnail.com  |  CSDN  |  简书

1. Description

2. Solution

**解析：**Version 1，遍历数组中的字符串，同时遍历s，如果数组中的字符不等于对应位置的字符，直接返回False，当s遍历结束时，判断数组中当前位置的字符串是否遍历完成，如果数组遍历结束，判断字符串s是否遍历完成。Version 2直接按单词比较。

• Version 1

class Solution:
    def isPrefixString(self, s: str, words: List[str]) -> bool:
        n = len(s)
        i = 0
        for word in words:
            for j in range(len(word)):
                if s[i] == word[j]:
                    i += 1
                else:
                    return False
                if i == n:
                    return j == len(word) - 1
        return i == n

• Version 2

class Solution:
    def isPrefixString(self, s: str, words: List[str]) -> bool:
        n = len(s)
        i = 0
        for word in words:
            m = len(word)
            if s[i:i+m] == word:
                i += m
            else:
                return False
            if i == n:
                return True
        return i == n

Reference

1. https://leetcode.com/problems/check-if-string-is-a-prefix-of-array/