Time: 4 ms (84.10%), Space: 8.7 MB (47.18%) - LeetHub

Author: JanaSabuj

pyramid-transition-matrix/pyramid-transition-matrix.cpp

@@ -0,0 +1,28 @@
+class Solution {
+    unordered_map<string, vector<char>> mp;
+public:
+    
+    bool dfs(string bottom, string tmp){
+        // base
+        if(bottom.size() == 1)
+            return true;
+        if(bottom.size() == tmp.size() + 1)
+            return dfs(tmp, "");
+        
+        // main
+        for(auto ch: mp[bottom.substr(tmp.size(), 2)]){
+            if(dfs(bottom, tmp + ch))
+                return true;            
+        }
+        
+        return false;
+    }
+    
+    bool pyramidTransition(string bottom, vector<string>& allowed) {
+        for(auto str: allowed){
+            mp[str.substr(0, 2)].push_back(str[2]);
+        }
+        
+        return dfs(bottom, "");
+    }
+};