weekly contest 371

Author: ZLBer

Diff for: README.md

@@ -5,6 +5,7 @@ Record leetcode contest and ideas every week, and encourage yourself to think mo
 leetcode url: <https://leetcode.cn/u/cctest/>
 
 
+* 🐼 [weekly contest 371](src/main/java/weekly/wk371.java)     暴力 | 模拟 | 贪心 | 字典树+异或
 * 🐼 [weekly contest 370](src/main/java/weekly/wk370.java)     有向图 | 有向图 | dfs | 树状数组or线段树
 * 🐼 [weekly contest 369](src/main/java/weekly/wk369.java)     模拟 | 贪心 | dp
 * 🐼 [weekly contest 368](src/main/java/weekly/wk368.java)     前后缀 | 前后缀 | 枚举 | 记忆化搜索

Diff for: src/main/java/weekly/wk371.java

@@ -0,0 +1,164 @@
+package weekly;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+public class wk371 {
+    //暴力
+ /*   public int maximumStrongPairXor(int[] nums) {
+        int ans = -1;
+        for (int i = 0; i < nums.length; i++) {
+            for (int j = 0; j < nums.length; j++) {
+                if (Math.abs(nums[i] - nums[j]) <= Math.min(nums[i], nums[j])) {
+                    ans = Math.max(nums[i] ^ nums[j], ans);
+                }
+
+            }
+        }
+        return ans;
+    }*/
+
+    //模拟
+    public List<String> findHighAccessEmployees(List<List<String>> access_times) {
+        List<int[]> list = new ArrayList<>(access_times.size());
+        for (int i = 0; i < access_times.size(); i++) {
+            list.add(new int[]{i, Integer.parseInt(access_times.get(i).get(1))});
+        }
+
+        Collections.sort(list, (a, b) -> a[1] - b[1]);
+
+        Map<String, List<Integer>> map = new HashMap<>();
+        for (int i = 0; i < list.size(); i++) {
+            String emp = access_times.get(list.get(i)[0]).get(0);
+            int time = list.get(i)[1];
+            if (!map.containsKey(emp)) map.put(emp, new ArrayList<>());
+            map.get(emp).add(time);
+        }
+
+        List<String> res = new ArrayList<>();
+        for (Map.Entry<String, List<Integer>> entry : map.entrySet()) {
+            List<Integer> value = entry.getValue();
+            for (int i = 2; i < value.size(); i++) {
+                if (help(value.get(i - 2), value.get(i)) <= 60) {
+                    res.add(entry.getKey());
+                    break;
+
+                }
+            }
+        }
+        return res;
+
+    }
+
+
+    int help(int a, int b) {
+        if (a / 100 == b / 100) {
+            return b - a;
+        } else if ((b / 100) - (a / 100) == 1) {
+            return b % 100 + (60 - a % 100);
+        } else return Integer.MAX_VALUE;
+    }
+
+
+    //贪心
+    public int minOperations(int[] nums1, int[] nums2) {
+        int v1 = help(nums1, nums2, nums1[nums1.length - 1], nums2[nums2.length - 1]);
+        int v2 = help(nums1, nums2, nums2[nums1.length - 1], nums1[nums2.length - 1]) + 1;
+        int v = Math.min(v1, v2);
+        if (v >= (int) 1e9 + 7) return -1;
+        return v;
+    }
+
+    int help(int[] nums1, int[] nums2, int a, int b) {
+        int ans = 0;
+        for (int i = 0; i < nums1.length - 1; i++) {
+            if (a >= nums1[i] && b >= nums2[i]) {
+
+            } else if (b >= nums1[i] && a >= nums2[i]) {
+                ans++;
+            } else {
+                return (int) 1e9 + 7;
+            }
+        }
+        return ans;
+    }
+
+
+    public int maximumStrongPairXor(int[] nums) {
+        Arrays.sort(nums);
+        int left = 0, right = 0;
+        int ans = 0;
+        Trie t = new Trie();
+
+        for (int i = 0; i < nums.length; i++) {
+            t.insert(nums[i]);
+            int x = nums[i];
+            while (nums[left] < (x + 1) / 2) {
+                t.remove(nums[left]);
+                left++;
+            }
+            ans=Math.max(ans,t.maxXor(nums[i]));
+        }
+        return ans;
+    }
+
+
+    class Node {
+        Node[] children = new Node[2];
+        int cnt; // 子树大小
+    }
+
+    class Trie {
+        private static final int HIGH_BIT = 19;
+        private Node root = new Node();
+
+        // 添加 val
+        public void insert(int val) {
+            Node cur = root;
+            for (int i = HIGH_BIT; i >= 0; i--) {
+                int bit = (val >> i) & 1;
+                if (cur.children[bit] == null) {
+                    cur.children[bit] = new Node();
+                }
+                cur = cur.children[bit];
+                cur.cnt++; // 维护子树大小
+            }
+        }
+
+        // 删除 val，但不删除节点
+        // 要求 val 必须在 trie 中
+        public void remove(int val) {
+            Node cur = root;
+            for (int i = HIGH_BIT; i >= 0; i--) {
+                cur = cur.children[(val >> i) & 1];
+                cur.cnt--; // 维护子树大小
+            }
+        }
+
+        // 返回 val 与 trie 中一个元素的最大异或和
+        // 要求 trie 不能为空
+        public int maxXor(int val) {
+            Node cur = root;
+            int ans = 0;
+            for (int i = HIGH_BIT; i >= 0; i--) {
+                int bit = (val >> i) & 1;
+                // 如果 cur.children[bit^1].cnt == 0，视作空节点
+                // 判断有没有相异的节点
+                if (cur.children[bit ^ 1] != null && cur.children[bit ^ 1].cnt > 0) {
+                    ans |= 1 << i; //相异直接+1即可
+                    bit ^= 1;
+                }
+                //这里省略了相同不加
+                cur = cur.children[bit];
+            }
+            return ans;
+        }
+    }
+
+}