LeetCode 0290 - Word Pattern

Reck Zhang

发布于 2021-08-11 11:48:12

1990

发布于 2021-08-11 11:48:12

文章被收录于专栏：Reck ZhangReck Zhang

Word Pattern

Desicription

Given a pattern and a string str, find if str follows the same pattern.

Here follow means a full match, such that there is a bijection between a letter in pattern and a non-empty word in str.

Example 1:

Input: pattern = "abba", str = "dog cat cat dog"
Output: true

Example 2:

Input:pattern = "abba", str = "dog cat cat fish"
Output: false

Example 3:

Input: pattern = "aaaa", str = "dog cat cat dog"
Output: false

Example 4:

Input: pattern = "abba", str = "dog dog dog dog"
Output: false

Notes: You may assume pattern contains only lowercase letters, and str contains lowercase letters separated by a single space.

Solution

class Solution {
public:
    bool wordPattern(string pattern, string str) {
        vector<string> vec_str;
        istringstream is(str);
        for(string s; is >> s; ) {
            vec_str.push_back(s);
        }
        if(pattern.size() != vec_str.size()) {
            return false;
        }
        map<char, int> pattern_map;
        map<string, int> string_map;
        for(int i = 0; i < pattern.size(); i++) {
            if(pattern_map[pattern[i]] != string_map[vec_str[i]]) {
                return false;
            }
            pattern_map[pattern[i]] = i + 1;
            string_map[vec_str[i]] = i + 1;
        }
        return true;
    }
};

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原始发表：2018-12-20，如有侵权请联系 cloudcommunity@tencent.com 删除

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