Create 1434.Number-of-Ways-to-Wear-Different-Hats-to-Each-Other.cpp

Dynamic_Programming/1434.Number-of-Ways-to-Wear-Different-Hats-to-Each-Other/1434.Number-of-Ways-to-Wear-Different-Hats-to-Each-Other.cpp

@@ -0,0 +1,38 @@
+class Solution {
+public:
+    int numberWays(vector<vector<int>>& hats) 
+    {
+        int n = hats.size();
+        unordered_map<int,vector<int>>Map;
+        for (int i=0; i<hats.size(); i++)
+            for (int j=0; j<hats[i].size(); j++)
+                Map[hats[i][j]].push_back(i);
+
+        vector<long>dp(1<<n, 0);
+        dp[0] = 1;
+        for (int p: Map[1])
+            dp[1<<p] = 1;
+        long M = 1e9+7;
+
+        for (int i=2; i<=40; i++)
+        {
+            auto dp2=dp;
+
+            for (int set = 0; set<(1<<n); set++)
+            {
+                for (int p: Map[i])
+                {
+                    if (((set>>p)&1)==0)
+                    {
+                        dp2[set+(1<<p)] += dp[set];
+                        dp2[set+(1<<p)]%=M;
+                    }
+                }
+            }
+
+            dp = dp2;
+        }
+
+        return dp[(1<<n)-1];                
+    }
+};