257周赛

src/main/java/com/code/leet/week/Solution257.java

@@ -0,0 +1,70 @@
+package com.code.leet.week;
+
+import com.code.leet.entiy.TwoArray;
+
+import java.math.BigInteger;
+import java.util.*;
+
+/**
+ * @description:
+ * @author: Administrator
+ * @date: 2021/8/22-10:29
+ */
+public class Solution257 {
+    public static void main(String[] args) {
+        Solution257 solution = new Solution257();
+//        TwoArray twoArray = new TwoArray("[[1,1],[2,1],[2,2],[1,2]]", true);
+//        System.out.println(solution.numberOfWeakCharacters(twoArray.getArr()));
+        System.out.println(solution.firstDayBeenInAllRooms(new int[]{0, 0}));
+    }
+
+    public int countQuadruplets(int[] nums) {
+        int count = 0;
+        for (int i = 0; i < nums.length; i++) {
+            for (int j = i + 1; j < nums.length; j++) {
+                for (int k = j + 1; k < nums.length; k++) {
+                    for (int l = k + 1; l < nums.length; l++) {
+                        if (nums[i] + nums[j] + nums[k] == nums[l]) {
+                            count++;
+                        }
+                    }
+                }
+            }
+        }
+        return count;
+    }
+
+    public int numberOfWeakCharacters(int[][] properties) {
+        Arrays.sort(properties, (o1, o2) -> o1[0] == o2[0] ? o2[1] - o1[1] : o2[0] - o1[0]);
+        TreeSet<Integer> set = new TreeSet<>();
+        int count = 0;
+        List<Integer> list = new ArrayList<>();
+        for (int i = 0; i < properties.length; i++) {
+            if (set.higher(properties[i][1]) != null) {
+                count++;
+            }
+            list.add(properties[i][1]);
+            if (i != properties.length - 1 && properties[i][0] != properties[i + 1][0]) {
+                set.addAll(list);
+                list.clear();
+            }
+        }
+        for (int i = properties.length - 1; i >= 0; i--) {
+            if (i != properties.length - 1 && properties[i][0] != properties[i + 1][0] && set.higher(properties[i][1]) != null) {
+                count++;
+            }
+            set.add(properties[i][1]);
+        }
+        return count;
+    }
+
+    public int firstDayBeenInAllRooms(int[] nextVisit) {
+        int[] dp = new int[nextVisit.length];
+        int[] sum = new int[nextVisit.length];
+        for (int i = 1; i < nextVisit.length; i++) {
+            sum[i] = dp[i - 1] - dp[nextVisit[i - 1]];
+            dp[i] = dp[i - 1] + sum[i];
+        }
+        return dp[nextVisit.length - 1];
+    }
+}