20180617

2018-06/2018-06-17/leetcode855.java

@@ -0,0 +1,44 @@
+class ExamRoom {
+    int N;
+    TreeSet<Integer> students;
+
+    public ExamRoom(int N) {
+        this.N = N;
+        students = new TreeSet();
+    }
+
+    public int seat() {
+        int student = 0;
+        if (students.size() > 0) {
+            int dist = students.first();
+            Integer prev = null;
+            for (Integer s: students) {
+                if (prev != null) {
+                    int d = (s - prev) / 2;
+                    if (d > dist) {
+                        dist = d;
+                        student = prev + d;
+                    }
+                }
+                prev = s;
+            }
+
+            // Considering the right-most seat.
+            if (N - 1 - students.last() > dist)
+                student = N - 1;
+        }
+
+        students.add(student);
+        return student;
+    }
+
+    public void leave(int p) {
+        students.remove(p);
+    }
+}
+/**
+ * Your ExamRoom object will be instantiated and called as such:
+ * ExamRoom obj = new ExamRoom(N);
+ * int param_1 = obj.seat();
+ * obj.leave(p);
+ */

README.md

@@ -289,4 +289,7 @@ Accept Game
 - leetcode795
 ### 2018-06-13
 - leetcode848 / 数据范围
-- leetcode851 / dfs + 记忆化搜索
+### 2018-06-14
+- leetcode851 / dfs + 记忆化搜索
+### 2018-06-17
+- leetcode855 / set