LeetCode:Word Pattern

Word Pattern

Total Accepted: 21299 Total Submissions: 77656 Difficulty: Easy

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.

Examples:

1. pattern = "abba", str = "dog cat cat dog" should return true.
2. pattern = "abba", str = "dog cat cat fish" should return false.
3. pattern = "aaaa", str = "dog cat cat dog" should return false.
4. pattern = "abba", str = "dog dog dog dog" should return false.

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

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code:

class Solution {public:    bool wordPattern(string pattern, string str) {        map<char, int> cmap;        map<string, int> smap;        int n = pattern.size();        istringstream in(str);        int i=0;        for(string word;in>>word;i++)        {            if(cmap[pattern[i]] != smap[word]) return false;            cmap[pattern[i]] = smap[word] = i+1;        }        return i==n;    }};