update 207 java, progress

README.md

@@ -899,7 +899,7 @@
 127| [Word Ladder](https://leetcode.com/problems/word-ladder/)| [Python](./leetcode_python/Breadth-First-Search/word-ladder.py) | _O(n * d)_   | _O(d)_ | Hard/Medium |good basic, check #126 Word Ladder II, `bfs`, `UBER`, `amazon`, `M$`, `fb`| AGAIN************** (9)
 130| [Surrounded Regions](https://leetcode.com/problems/surrounded-regions/)| [Python](./leetcode_python/Breadth-First-Search/surrounded-regions.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/BFS/SurroundedRegions.java) | _O(m + n)_ | | Medium |`bfs`, `dfs`,`union find`,good basic, `amazon`| AGAIN*********** (5)
 133| [Clone Graph](https://leetcode.com/problems/clone-graph/)| [Python](./leetcode_python/Breadth-First-Search/clone-graph.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/Graph/CloneGraph.java)  | _O(n)_ | _O(n)_  | Medium  |Curated Top 75, good trick, `check #138 Copy List with Random Pointer `,`graph`,`dfs`,`bfs`, `UBER`, `google`,`amazon`,`fb`|  AGAIN**************** (9) (MUST)
-207| [Course Schedule](https://leetcode.com/problems/course-schedule/)| [Python](./leetcode_python/Breadth-First-Search/course-schedule.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/BFS/CourseSchedule.java)  | _O(\|V\| + \|E\|)_   |  _O(\|E\|)_  |  Medium  |Curated Top 75, Topological Sort, backtrack, `good trick`,`dfs`, `bfs` , `amazon`,`fb`| AGAIN**************** (12) (MUST) 
+207| [Course Schedule](https://leetcode.com/problems/course-schedule/)| [Python](./leetcode_python/Breadth-First-Search/course-schedule.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/BFS/CourseSchedule.java)  | _O(\|V\| + \|E\|)_   |  _O(\|E\|)_  |  Medium  |Curated Top 75, Topological Sort, backtrack, `good trick`,`dfs`, `bfs` , `amazon`,`fb`| AGAIN**************** (13) (MUST) 
 210| [Course Schedule II](https://leetcode.com/problems/course-schedule-ii/)| [Python](./leetcode_python/Breadth-First-Search/course-schedule-ii.py)    | _O(\|V\| + \|E\|)_   | _O(\|E\|)_  | Medium  |Topological Sort,check `# 207 Course Schedule ` first, `dfs`, `bfs` ,`amazon` ,`fb` | AGAIN********* (9) (again)
 261| [Graph Valid Tree](https://leetcode.com/problems/graph-valid-tree/)| [Python](./leetcode_python/Breadth-First-Search/graph-valid-tree.py)    | _O(\|V\| + \|E\|)_    | _O(\|V\| + \|E\|)_   | Medium  | Curated Top 75, AGAIN, bfs, dfs, grpah, 🔒, `graph`,`quick union`,`union find` ,`google`,`amazon`,`fb`| AGAIN************* (8)
 286| [Walls and Gates](https://leetcode.com/problems/walls-and-gates/)|  [Python](./leetcode_python/Breadth-First-Search/walls-and-gates.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/BFS/WallsAndGates.java)| _O(m * n)_ | _O(g)_  | Medium  | 🔒, `dfs`, `bfs` , `good basic`, `google`,`amazon`,`FB`| AGAIN******** (7)

data/progress.txt

@@ -1,3 +1,4 @@
+20240309: 207(again!!!)
 20240308: 152,153(again),190,191,198,200,206(again)
 20240307: 139(again),141,143(again)
 20240306: 121,124(again),125,128,133(again)

data/to_review.txt

@@ -1,3 +1,4 @@
+2024-05-03 -> ['207(again!!!)']
 2024-05-02 -> ['152,153(again),190,191,198,200,206(again)']
 2024-05-01 -> ['139(again),141,143(again)']
 2024-04-30 -> ['121,124(again),125,128,133(again)']
@@ -7,6 +8,7 @@
 2024-04-24 -> ['39,48(again),49,53,54']
 2024-04-23 -> ['20,21,23,33(again)']
 2024-04-22 -> ['1,3,5,4,19']
+2024-04-12 -> ['207(again!!!)']
 2024-04-11 -> ['152,153(again),190,191,198,200,206(again)']
 2024-04-10 -> ['139(again),141,143(again)']
 2024-04-09 -> ['121,124(again),125,128,133(again)']
@@ -16,24 +18,26 @@
 2024-04-03 -> ['39,48(again),49,53,54']
 2024-04-02 -> ['20,21,23,33(again)']
 2024-04-01 -> ['1,3,5,4,19']
+2024-03-30 -> ['207(again!!!)']
 2024-03-29 -> ['152,153(again),190,191,198,200,206(again)']
 2024-03-28 -> ['139(again),141,143(again)']
 2024-03-27 -> ['121,124(again),125,128,133(again)']
 2024-03-26 -> ['100,102,104,105(again)']
 2024-03-25 -> ['73,76,79(again),91,25']
 2024-03-24 -> ['55(again),56,62,70']
+2024-03-22 -> ['207(again!!!)']
 2024-03-21 -> ['152,153(again),190,191,198,200,206(again)', '39,48(again),49,53,54']
 2024-03-20 -> ['139(again),141,143(again)', '20,21,23,33(again)']
 2024-03-19 -> ['121,124(again),125,128,133(again)', '1,3,5,4,19']
 2024-03-18 -> ['100,102,104,105(again)']
-2024-03-17 -> ['73,76,79(again),91,25']
+2024-03-17 -> ['207(again!!!)', '73,76,79(again),91,25']
 2024-03-16 -> ['152,153(again),190,191,198,200,206(again)', '55(again),56,62,70']
 2024-03-15 -> ['139(again),141,143(again)']
-2024-03-14 -> ['121,124(again),125,128,133(again)']
+2024-03-14 -> ['207(again!!!)', '121,124(again),125,128,133(again)']
 2024-03-13 -> ['152,153(again),190,191,198,200,206(again)', '100,102,104,105(again)', '39,48(again),49,53,54']
-2024-03-12 -> ['139(again),141,143(again)', '73,76,79(again),91,25', '20,21,23,33(again)']
-2024-03-11 -> ['152,153(again),190,191,198,200,206(again)', '121,124(again),125,128,133(again)', '55(again),56,62,70', '1,3,5,4,19']
-2024-03-10 -> ['152,153(again),190,191,198,200,206(again)', '139(again),141,143(again)', '100,102,104,105(again)']
+2024-03-12 -> ['207(again!!!)', '139(again),141,143(again)', '73,76,79(again),91,25', '20,21,23,33(again)']
+2024-03-11 -> ['207(again!!!)', '152,153(again),190,191,198,200,206(again)', '121,124(again),125,128,133(again)', '55(again),56,62,70', '1,3,5,4,19']
+2024-03-10 -> ['207(again!!!)', '152,153(again),190,191,198,200,206(again)', '139(again),141,143(again)', '100,102,104,105(again)']
 2024-03-09 -> ['152,153(again),190,191,198,200,206(again)', '139(again),141,143(again)', '121,124(again),125,128,133(again)', '73,76,79(again),91,25']
 2024-03-08 -> ['139(again),141,143(again)', '121,124(again),125,128,133(again)', '100,102,104,105(again)', '55(again),56,62,70', '39,48(again),49,53,54']
 2024-03-07 -> ['121,124(again),125,128,133(again)', '100,102,104,105(again)', '73,76,79(again),91,25', '20,21,23,33(again)']

leetcode_java/src/main/java/LeetCodeJava/BFS/CourseSchedule.java

@@ -69,7 +69,7 @@ public class CourseSchedule {
 //    }
 
     // V1
-    // IDEA : DFS
+    // IDEA : BFS
     // https://leetcode.com/problems/course-schedule/solutions/58775/my-java-bfs-solution/
     public boolean canFinish(int numCourses, int[][] prerequisites) {
         Map<Integer, ArrayList<Integer>> map = new HashMap<Integer, ArrayList<Integer>>();
@@ -81,7 +81,10 @@ public boolean canFinish(int numCourses, int[][] prerequisites) {
         }
         for (int i = 0; i < prerequisites.length; i++) {
             map.get(prerequisites[i][0]).add(prerequisites[i][1]);
-            indegree[prerequisites[i][1]]++;
+            // V1
+            //indegree[prerequisites[i][1]]++;
+            // V2
+            indegree[prerequisites[i][1]] += 1;
         }
         for (int i = 0; i < numCourses; i++) {
             if (indegree[i] == 0) {
@@ -91,9 +94,19 @@ public boolean canFinish(int numCourses, int[][] prerequisites) {
         while (!queue.isEmpty()) {
             int current = queue.poll();
             for (int i : map.get(current)) {
-                if (--indegree[i] == 0) {
+
+                  // V1
+//                if (--indegree[i] == 0) {
+//                    queue.offer(i);
+//                }
+
+                // V2
+                if (indegree[i] == 1) {
                     queue.offer(i);
+                } else {
+                    indegree[i] -= 1;
                 }
+
             }
             count--;
         }