solved 풍선 터트리기 - 2003.79ms 281MB

Programmers/풍선터트리기/풍선터트리기_강정훈.java

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+import java.util.*;
+class Solution {
+    private int leftMinValue = Integer.MAX_VALUE;
+    private int leftSecondMinValue = Integer.MAX_VALUE;
+    private Set<Integer> visited;
+    private Queue<Integer> rightQueue;
+    public int solution(int[] a) {
+        if(a.length <= 2) {
+            return a.length;
+        }
+        int answer = 0;
+        visited = new HashSet<>();
+        rightQueue = new PriorityQueue<>();
+        for (int baloon : a) {
+            rightQueue.add(baloon);
+        }
+        rightQueue.add(Integer.MAX_VALUE);
+        rightQueue.add(Integer.MAX_VALUE);
+        int leftMinValue = Integer.MAX_VALUE;
+        int leftSecondMinValue = Integer.MAX_VALUE;
+        for (int baloon : a) {
+            visited.add(baloon);
+            int[] rightMinValues = getRightMinValues();
+            int rightMinValue = rightMinValues[0];
+            int rightSecondMinValue = rightMinValues[1];
+            if (canPop(baloon, leftMinValue, leftSecondMinValue, rightMinValue, rightSecondMinValue)) {
+                answer++;
+            }
+            if (leftMinValue > baloon) {
+                leftSecondMinValue = leftMinValue;
+                leftMinValue = baloon;
+            } else if (leftMinValue < baloon && baloon < leftSecondMinValue) {
+                leftSecondMinValue = baloon;
+            }
+        }
+        return answer;
+    }
+    private int[] getRightMinValues() {
+        int[] rightMinValues = new int[2];
+        while(true) {
+            int candidate = rightQueue.peek();
+            if (visited.contains(candidate)) {
+                rightQueue.poll();
+            } else {
+                if (rightMinValues[0] != 0) {
+                    rightMinValues[1] = candidate;
+                    rightQueue.add(rightMinValues[0]);
+                    break;
+                }
+                rightQueue.poll();
+                rightMinValues[0] = candidate;
+            }
+        }
+        return rightMinValues;
+    }
+    private boolean canPop(int baloon, int leftMinValue, int leftSecondMinValue, int rightMinValue, int rightSecondMinValue) {
+        if (leftMinValue > baloon && rightMinValue > baloon) {
+            return true;
+        } else if (leftMinValue > baloon && rightMinValue < baloon) {
+            return true;
+        } else if (leftMinValue < baloon && rightMinValue > baloon) {
+            return true;
+        }
+        return false;
+    }
+}