Update and rename 2320.Count-Number-of-Ways-to-Place-Houses.cpp to 23…

…20.Count-Number-of-Ways-to-Place-Houses_v1.cpp
lijing-code · Jun 27, 2022 · 89cbb34 · 89cbb34
1 parent 8f62433
commit 89cbb34
Showing 1 changed file with 6 additions and 4 deletions.
diff --git a/....Count-Number-of-Ways-to-Place-Houses.cpp → ...unt-Number-of-Ways-to-Place-Houses_v1.cpp b/....Count-Number-of-Ways-to-Place-Houses.cpp → ...unt-Number-of-Ways-to-Place-Houses_v1.cpp
@@ -1,14 +1,16 @@
 using LL = long long;
 LL M = 1e9+7;
 class Solution {
-    LL dp[10001][2];
+    LL dp[10001][2]; 
+    // dp[i][0]: the # of plans so that there is no building at the i-th plot
+    // dp[i][1]: the # of plans so that there is a building at the i-th plot
 public:
     int countHousePlacements(int n) 
     {                
-        dp[1][0] = 1;
-        dp[1][1] = 1;
+        dp[0][0] = 1;
+        dp[0][1] = 0;
 
-        for (int i=2; i<=n; i++)
+        for (int i=1; i<=n; i++)
         {
             dp[i][0] = (dp[i-1][0] + dp[i-1][1])%M;
             dp[i][1] = dp[i-1][0];