[WIP] Add calculation for distance from point to line

leetcode/Study Plan/128. 最长连续序列/1.cpp

@@ -0,0 +1,44 @@
+#include <algorithm>
+#include <unordered_set>
+#include <vector>
+
+class Solution {
+   public:
+    int longestConsecutive(std::vector<int> &nums) {
+        // 1. 将所有元素存入哈希集合
+        std::unordered_set<int> hmap(nums.begin(), nums.end());
+        int ans = 0;
+
+        // 获取不同元素的总个数 M
+        int M = hmap.size();
+
+        for (auto x : nums) {
+
+            // 核心优化：只从连续序列的起点开始检查
+            // 如果 x-1 存在，说明 x 不是起点，跳过
+            if (hmap.count(x - 1))
+                continue;
+
+            int length = 1;
+            int y = x + 1;
+
+            // 延伸序列
+            while (hmap.count(y)) {
+                length++;
+                y++;
+            }
+
+            // 更新答案
+            ans = std::max(ans, length);
+
+            // 【额外的剪枝优化】: 检查当前找到的最长长度 ans
+            // 如果 ans * 2 > M，那么后续找到更长的链的可能性极低（除非当前 ans 已经是最优解）
+            // 注意：这里 M 是 hmap 的大小，也就是不同元素的个数。
+            if (ans * 2 > M) {
+                return ans;
+            }
+        }
+
+        return ans;
+    }
+};

leetcode/Study Plan/128. 最长连续序列/1.go

@@ -0,0 +1,33 @@
+func longestConsecutive(nums []int) int {
+	numset := make(map[int]bool)
+	for _,v := range nums{
+		numset[v] = true
+	}
+	ans := 0
+	for x := range numset{
+		_,existsPrev := numset[x-1]
+		if existsPrev{
+			continue
+		}
+		currentNum := x
+		currentLength := 1
+		for{
+			_,existsNext := numset[currentNum+1]
+			if !existsNext{
+				break
+			}
+			currentNum++
+			currentLength++
+		}
+		ans = max(ans,currentLength)
+	}
+	return ans
+}
+
+// func max(a,b int)int{
+// 	if a > b{
+// 		return a
+// 	}else{
+// 		return b
+// 	}
+// }

leetcode/Study Plan/3433. 统计用户被提及情况/1.go

@@ -0,0 +1,54 @@
+func countMentions(numberOfUsers int, events [][]string) []int {
+	ans := make([]int, numberOfUsers)
+	// Event struct: timestamp, type (1=offline, -1=online, 2=HERE mention), user id
+	type event struct {
+		timestamp, type_, id int
+	}
+	es := []event{}
+	all := 0
+	// Process raw events and separate them into individual event objects
+	for _, e := range events {
+		curT, _ := strconv.Atoi(e[1])
+		mention := e[2]
+		if e[0] == "OFFLINE" {
+			// Create offline(1) and online(-1) events 60 seconds later
+			i, _ := strconv.Atoi(mention)
+			es = append(es, event{curT, 1, i}, event{curT + 60, -1, i})
+		} else if mention == "ALL" {
+			all++
+		} else if mention == "HERE" {
+			// Increment all user mentions for HERE events (process later)
+			all++
+			es = append(es, event{curT, 2, -1})
+		} else {
+			// Direct user mentions: add immediately
+			for _, s := range strings.Split(mention, " ") {
+				i, _ := strconv.Atoi(s[2:])
+				ans[i]++
+			}
+		}
+	}
+
+	// Sort events by timestamp, then by type (process in correct order)
+	slices.SortFunc(es, func(a, b event) int {
+		return cmp.Or(a.timestamp-b.timestamp, a.type_-b.type_)
+	})
+
+	// Calculate HERE mentions: count online users at each HERE event
+	here := 0
+	for _, e := range es {
+		if e.type_ == 2 {
+			// HERE mention: increment all currently online users by 'here' count
+			here++
+		} else {
+			// OFFLINE/ONLINE event: update online status (1 removes, -1 adds)
+			ans[e.id] += e.type_ * here
+		}
+	}
+
+	// Add ALL mentions to all users
+	for i := range ans {
+		ans[i] += all
+	}
+	return ans
+}

leetcode/Study Plan/3433. 统计用户被提及情况/1.py

@@ -0,0 +1,30 @@
+class Solution:
+    def countMentions(self, numberOfUsers: int, events: List[List[str]]) -> List[int]:
+        # Sort events by timestamp, then by event type (to process in chronological order)
+        events.sort(key = lambda e:(int(e[1]),e[0][2]))
+
+        # ans[i] stores the mention count for user i
+        ans = [0]*numberOfUsers
+        # online_t[i] stores when user i will be back online (0 means currently online)
+        online_t = [0]*numberOfUsers
+
+        for type_,timestamp,mention in events:
+            curr_t = int(timestamp)
+            # Handle OFFLINE event: user goes offline for 60 seconds
+            if type_ == "OFFLINE":
+                online_t[int(mention)] = curr_t + 60 
+            # Handle ALL mentions: all users are mentioned
+            elif mention == "ALL":
+                for i in range(numberOfUsers):
+                    ans[i] += 1 
+            # Handle HERE mentions: only currently online users are mentioned
+            elif mention == "HERE":
+                for i,t in enumerate(online_t):
+                    if curr_t >= t:
+                        ans[i] += 1
+            # Handle individual user mentions (e.g., "id0 id1 id2")
+            else:
+                for s in mention.split():
+                    # Extract user ID from "id<number>" format
+                    ans[int(s[2:])] += 1
+        return ans

leetcode/Study Plan/3606. 优惠券校验器/1.cpp

@@ -0,0 +1,64 @@
+#include<vector>
+#include<string>
+#include<algorithm>
+using namespace std;
+class Solution {
+public:
+    vector<string> validateCoupons(vector<string>& code, vector<string>& businessLine, vector<bool>& isActive) {
+        int n = code.size();
+        // Store pairs of (businessLine priority, code)
+        vector<pair<int, string>> ans;
+        for(int i = 0; i < n; ++i)
+        {
+            if(isActive[i] && isValid(code[i], businessLine[i]))
+            {
+                int priority = getBusinessPriority(businessLine[i]);
+                ans.push_back({priority, code[i]});
+            }
+        }
+        // Sort by priority first, then by code lexicographically
+        sort(ans.begin(), ans.end());
+
+        // Extract just the codes for the result
+        vector<string> result;
+        for(auto &p : ans)
+        {
+            result.push_back(p.second);
+        }
+        return result;
+    }
+
+private:
+    vector<string> vaild_business = {
+        "electronics",
+        "grocery",
+        "pharmacy",
+        "restaurant"
+    };
+
+    // Get priority of business line (0 = highest priority)
+    int getBusinessPriority(const string &b)
+    {
+        auto it = find(vaild_business.begin(), vaild_business.end(), b);
+        if(it == vaild_business.end()) return -1;
+        return it - vaild_business.begin();
+    }
+
+    bool isValid(const string &c, const string &b)
+    {
+        if(find(vaild_business.begin(), vaild_business.end(), b) == vaild_business.end())
+            return false;
+        if(c == "")
+            return false;
+        for(auto ch : c)
+        {
+            bool isAlpha = (ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z');
+            bool isDigit = ch >= '0' && ch <= '9';
+            bool isUnderscore = ch == '_';
+
+            if(!isAlpha && !isDigit && !isUnderscore)
+                return false;
+        }
+        return true;
+    }
+};

leetcode/高频 SQL 50 题（基础版）/1378. 使用唯一标识码替换员工ID.sql

@@ -0,0 +1,2 @@
+select u.unique_id,e.name from Employees as e left join EmployeeUNI as u 
+on e.id = u.id;

niuke/practice/noob/noob69 最厉害的学生/1.cpp

@@ -0,0 +1,74 @@
+#include <algorithm>
+#include <functional>
+#include <iomanip>
+#include <iostream>
+#include <queue>
+#include <string>
+#include <unordered_map>
+#include <vector>
+#define il inline
+#define endl '\n'
+using namespace std;
+
+#define pb push_back
+#define fastio                   \
+    ios::sync_with_stdio(false); \
+    cin.tie(0);
+
+typedef long long ll;
+typedef unsigned long long ull;
+
+const ll N = 5e5 + 5, mod = 1e9 + 7, inf = 2e18;
+const double eps = 1e-9;
+const double PI = 3.1415926;
+
+class Student {
+   public:
+    string name;
+    unordered_map<string, int> scores = {
+        {"chinese", 0},
+        {"math", 0},
+        {"english", 0},
+    };
+    int total_score = 0;
+
+    Student(string _name, int math, int chinese, int english) : name(_name) {
+        scores["chinese"] = chinese;
+        scores["math"] = math;
+        scores["english"] = english;
+        total_score = chinese + math + english;
+    }
+};
+
+auto cmp = [](const Student &a, const Student &b) {
+    return a.total_score < b.total_score; // Max heap: highest score on top
+};
+
+priority_queue<Student, vector<Student>, decltype(cmp)> pq(cmp);
+
+il void solve() {
+    string name;
+    int chinese, math, english;
+    cin >> name >> chinese >> math >> english;
+    Student stu(name, math, chinese, english);
+    pq.push(stu);
+
+}
+
+int main() {
+    fastio;
+
+    int t = 1;
+    cin >> t;
+
+    while (t--) {
+        solve();
+    }
+
+    if (!pq.empty()) {
+        Student top_student = pq.top();
+        cout << top_student.name << " " << top_student.scores["chinese"] << " " << top_student.scores["math"] << " "
+             << top_student.scores["english"] << endl;
+    }
+    return 0;
+}

niuke/practice/noob/noob70 两点间距离/1.cpp

@@ -0,0 +1,24 @@
+/**
+ * struct Point {
+ *	int x;
+ *	int y;
+ *	Point(int xx, int yy) : x(xx), y(yy) {}
+ * };
+ */
+class Solution {
+public:
+    /**
+     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
+     *
+     * 计算A点与B点之间的距离
+     * @param point_A Point类 A点
+     * @param point_B Point类 B点
+     * @return double浮点型
+     */
+    double calculateDistance(Point point_A, Point point_B) {
+        // write code here
+        double dx = static_cast<double>(point_A.x - point_B.x);
+        double dy = static_cast<double>(point_A.y - point_B.y);
+        return sqrt(dx * dx + dy * dy);
+    }
+};