From bcb6cde23eda3c31fb3360caeb58a2b461811bcd Mon Sep 17 00:00:00 2001
From: ShusenTang <tangshusen@pku.edu.cn>
Date: Sat, 25 Jul 2020 11:12:30 +0800
Subject: [PATCH] Update 290. Word Pattern.md

---
 solutions/290. Word Pattern.md | 36 ++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/solutions/290. Word Pattern.md b/solutions/290. Word Pattern.md
index c70e8b3..f53cdc9 100644
--- a/solutions/290. Word Pattern.md	
+++ b/solutions/290. Word Pattern.md	
@@ -3,6 +3,11 @@
 类似[205. Isomorphic Strings](https://leetcode.com/problems/isomorphic-strings/description/), 所以解题思路基本一样。   
 将pattern和str中个每个元素都用一个数代替,这个数代表了该元素是第几个出现的(如 "abba" -> 1221, "dog cat cat dog" -> 1221), 则结果应该是一样的。
 为了记录是否出现过，pattern用一个长度为26的数组实现，str用map来实现，此外还用一个count计数。
+
+更新：
+
+可以用`istringstream`很方便地将`str`按照空格分开。
+
 # C++
 ```C++
 class Solution {
@@ -32,3 +37,34 @@ public:
     }
 };
 ```
+
+更新：
+``` C++
+class Solution {
+public:
+    bool wordPattern(string pattern, string str) {
+        unordered_map<char, int>c_mp;
+        vector<int>c2int;
+        unordered_map<string, int>str_mp;
+                
+        int count = 0;
+        for(char c: pattern){
+            if(c_mp.find(c) == c_mp.end()) c_mp[c] = count++;
+            c2int.push_back(c_mp[c]);
+        }
+        
+        count = 0;
+        int i = 0;
+        string cur;
+        istringstream iss(str);
+        while(iss.good()){ // or !iss.eof()
+            iss >> cur;
+            if(str_mp.find(cur) == str_mp.end()) str_mp[cur] = count++;
+            if(i >= c2int.size() || c2int[i] != str_mp[cur]) return false;
+            i++;
+        }
+        
+        return i == c2int.size();
+    }
+};
+```