Update 1997.First-Day-Where-You-Have-Been-in-All-the-Rooms.cpp

wisdompeak · web-flow · commit 6160937133fa · 2021-09-06T17:11:02.000-07:00
diff --git a/Others/1997.First-Day-Where-You-Have-Been-in-All-the-Rooms/1997.First-Day-Where-You-Have-Been-in-All-the-Rooms.cpp b/Others/1997.First-Day-Where-You-Have-Been-in-All-the-Rooms/1997.First-Day-Where-You-Have-Been-in-All-the-Rooms.cpp
@@ -1,22 +1,17 @@
 class Solution {
     long dp[100000];    
     long M = 1e9+7;
-    int n;
 public:
     int firstDayBeenInAllRooms(vector<int>& nextVisit) 
     {
         n = nextVisit.size();
         dp[0] = 0;
-        dp[1] = 2;
-        long ret = 2;
-        for (int i=1; i<n-1; i++)
+        for (int i=0; i<n-1; i++)
         {
             int prev = nextVisit[i];            
             dp[i+1] = dp[i] + (dp[i]-dp[prev] + M +1) % M + 1;            
             dp[i+1] %= M;
         }
         return dp[n-1];        
     }
-    
-    
 };

Original file line number	Diff line number	Diff line change
`@@ -1,22 +1,17 @@`
`1`	`1`	`class Solution {`
`2`	`2`	`long dp[100000];`
`3`	`3`	`long M = 1e9+7;`
`4`		`- int n;`
`5`	`4`	`public:`
`6`	`5`	`int firstDayBeenInAllRooms(vector<int>& nextVisit)`
`7`	`6`	`{`
`8`	`7`	`n = nextVisit.size();`
`9`	`8`	`dp[0] = 0;`
`10`		`- dp[1] = 2;`
`11`		`- long ret = 2;`
`12`		`- for (int i=1; i<n-1; i++)`
	`9`	`+ for (int i=0; i<n-1; i++)`
`13`	`10`	`{`
`14`	`11`	`int prev = nextVisit[i];`
`15`	`12`	`dp[i+1] = dp[i] + (dp[i]-dp[prev] + M +1) % M + 1;`
`16`	`13`	`dp[i+1] %= M;`
`17`	`14`	`}`
`18`	`15`	`return dp[n-1];`
`19`	`16`	`}`
`20`		`-`
`21`		`-`
`22`	`17`	`};`