From a7babb87d2c4be5b51c4c43a0295e813d1dcb769 Mon Sep 17 00:00:00 2001
From: Meng Laijun <mlj1991@gmail.com>
Date: Sat, 19 Sep 2020 22:24:51 +0800
Subject: [PATCH] Add 2020-Q3/6.cpp

---
 contest/season/2020-Q3/6.cpp | 223 +++++++++++++++++++++++++++++++++++
 1 file changed, 223 insertions(+)
 create mode 100644 contest/season/2020-Q3/6.cpp

diff --git a/contest/season/2020-Q3/6.cpp b/contest/season/2020-Q3/6.cpp
new file mode 100644
index 0000000..a8398c0
--- /dev/null
+++ b/contest/season/2020-Q3/6.cpp
@@ -0,0 +1,223 @@
+#include <iostream>
+#include <cstdio>
+#include <string>
+#include <vector>
+#include <cmath>
+#include <algorithm>
+#include <map>
+#include <unordered_map>
+
+using namespace std;
+
+struct Info {
+  int circle;
+  int index;
+  int d;
+};
+
+class BlackBox {
+private:
+  int n;
+  int m;
+  unordered_map<int, Info> map_info_;
+  vector< map<int, int> > vec_circle_;
+  vector< map<int, int> > vec_circle2_;
+  vector<bool> is_circle_;
+
+  int get_num(int x, int y) {
+    if (x == 0) {
+      return n+m+m+y;
+    }
+    if (x == m) {
+      return n+m-y;
+    }
+    if (y == 0) {
+      return n+m+m-x;
+    }
+    if (y == n) {
+      return x;
+    }
+    return -1;
+  }
+
+  void get_next(int &num, int &d) {
+    int x = 0;
+    int y = 0;
+    if (num < m) {
+      x = num;
+      y = n;
+      if (d == 1) {
+        int p = min(x, y);
+        x -= p;
+        y -= p;
+      } else {
+        int p = min(m-x, y);
+        x += p;
+        y -= p;
+      }
+    } else if (num < n+m) {
+      x = m;
+      y = (n+m)-num;
+      if (d ==1) {
+        int p = min(x, y);
+        x -= p;
+        y -= p;
+      } else {
+        int p = min(x, n-y);
+        x -= p;
+        y += p;
+      }
+    } else if (num < n+m+m) {
+      x = (n+m+m)-num;
+      y = 0;
+      if (d == 1) {
+        int p = min(m-x, n-y);
+        x += p;
+        y += p;
+      } else {
+        int p = min(x, n-y);
+        x -= p;
+        y += p;
+      }
+    } else {
+      x = 0;
+      y = num-(n+m+m);
+      if (d == 1) {
+        int p = min(m-x, n-y);
+        x += p;
+        y += p;
+      } else {
+        int p = min(m-x, y);
+        x += p;
+        y -= p;
+      }
+    }
+    d = -d;
+    num = get_num(x, y);
+  }
+
+  void find_circle(int num, int d) {
+    if (map_info_.find(num) != map_info_.end()) {
+      return;
+    }
+
+    map<int, int> root;
+    vec_circle_.push_back(root);
+    vec_circle2_.push_back(root);
+    int circle = vec_circle_.size()-1;
+    int index = 0;
+    int now = num;
+
+    Info info;
+    info.circle = circle;
+    info.index = index;
+    info.d = d;
+    map_info_[now] = info;
+
+    //cout << circle << ": ";
+    //cout << now << "," << d << " ";
+    while (1) {
+      get_next(now, d);
+      if (now == num) {
+        is_circle_.push_back(true);
+        break;
+      }
+      index++;
+      //cout << now << "," << d << " ";
+
+      Info info;
+      info.circle = circle;
+      info.index = index;
+      info.d = d;
+      map_info_[now] = info;
+
+      if (now == 0 || now == m || now == n+m || now == n+m+m) {
+        is_circle_.push_back(false);
+        break;
+      }
+    }
+    //cout << endl;
+  }
+
+  void init() {
+    find_circle(0, -1);
+    find_circle(n+m, -1);
+    find_circle(m, 1);
+    find_circle(n+m+m, 1);
+    for (int i = 0; i != (n+m)*2; i++) {
+      find_circle(i, 1);
+    }
+  }
+
+public:
+  BlackBox(int n, int m) {
+    this->n = n;
+    this->m = m;
+    init();
+  }
+
+  int open(int index, int direction) {
+    int c = map_info_[index].circle;
+    int i = map_info_[index].index;
+    int d = map_info_[index].d;
+    map<int, int> &circle(vec_circle_[c]);
+    map<int, int> &circle2(vec_circle2_[c]);
+    circle[i] = index;
+    circle2[-i] = index;
+    bool upper = true;
+    if (direction != d) {
+      upper = false;
+    }
+    
+    map<int, int>::iterator iter;
+    if (upper) {
+      iter = circle.upper_bound(i);
+      if (iter != circle.end()) {
+        return iter->second;
+      }
+      if (is_circle_[c]) {
+        return circle.upper_bound(-1)->second;
+      }
+      return index;
+    } else {
+      iter = circle2.upper_bound(-i);
+      if (iter != circle2.end()) {
+        return iter->second;
+      }
+      if (is_circle_[c]) {
+        return circle2.upper_bound(-(n+n+m+m))->second;
+      }
+      return index;
+    }
+  }
+
+  void close(int index) {
+    int c = map_info_[index].circle;
+    int i = map_info_[index].index;
+    vec_circle_[c].erase(vec_circle_[c].find(i));
+    vec_circle2_[c].erase(vec_circle2_[c].find(-i));
+  }
+};
+
+int main() {
+  //Your BlackBox object will be instantiated and called as such:
+  //int n = 2;
+  //int m = 3;
+  //BlackBox* obj = new BlackBox(n, m);
+  //cout << obj->open(6, -1) << endl;
+  //cout << obj->open(4, -1) << endl;
+  //cout << obj->open(0, -1) << endl;
+  //obj->close(6);
+  //cout << obj->open(0, -1) << endl;
+  int n = 3;
+  int m = 3;
+  BlackBox* obj = new BlackBox(n, m);
+  cout << obj->open(1, -1) << endl;
+  cout << obj->open(5, 1) << endl;
+  cout << obj->open(11, -1) << endl;
+  cout << obj->open(11, 1) << endl;
+  obj->close(1);
+  cout << obj->open(11, 1) << endl;
+  obj->close(5);
+  cout << obj->open(11, -1) << endl;
+}