From 5555c136516803ba8578edd6d995f305901060f3 Mon Sep 17 00:00:00 2001 From: yanglbme Date: Mon, 26 Jun 2023 15:06:27 +0800 Subject: [PATCH] feat: add solutions to lc problem: No.2747 No.2747.Count Zero Request Servers --- .../2747.Count Zero Request Servers/README.md | 158 +++++++++++++++++- .../README_EN.md | 150 ++++++++++++++++- .../Solution.cpp | 31 ++++ .../Solution.go | 29 ++++ .../Solution.java | 29 ++++ .../Solution.py | 20 +++ .../Solution.ts | 34 ++++ 7 files changed, 445 insertions(+), 6 deletions(-) create mode 100644 solution/2700-2799/2747.Count Zero Request Servers/Solution.cpp create mode 100644 solution/2700-2799/2747.Count Zero Request Servers/Solution.go create mode 100644 solution/2700-2799/2747.Count Zero Request Servers/Solution.java create mode 100644 solution/2700-2799/2747.Count Zero Request Servers/Solution.py create mode 100644 solution/2700-2799/2747.Count Zero Request Servers/Solution.ts diff --git a/solution/2700-2799/2747.Count Zero Request Servers/README.md b/solution/2700-2799/2747.Count Zero Request Servers/README.md index a90f74ac34f56..f89fbc600fd38 100644 --- a/solution/2700-2799/2747.Count Zero Request Servers/README.md +++ b/solution/2700-2799/2747.Count Zero Request Servers/README.md @@ -55,6 +55,14 @@ +**方法一：离线查询 + 排序 + 双指针** + +我们可以将所有的查询按照时间从小到大排序，然后按照时间顺序依次处理每个查询。 + +对于每个查询 $q = (r, i)$，其窗口左边界为 $l = r - x$，我们需要统计在窗口 $[l, r]$ 内有多少个服务器收到了请求。我们用双指针 $j$ 和 $k$ 分别维护窗口的左右边界，初始时 $j = k = 0$。每一次，如果 $k$ 指向的日志的时间小于等于 $r$，我们就将其加入到窗口中，然后将 $k$ 向右移动一位。如果 $j$ 指向的日志的时间小于 $l$，我们就将其从窗口中移除，然后将 $j$ 向右移动一位。在移动的过程中，我们需要统计窗口中有多少个不同的服务器，这可以使用哈希表来实现。移动结束后，当前时间区间中没有收到请求的服务器数目就是 $n$ 减去哈希表中不同的服务器数目。 + +时间复杂度 $O(l \times \log l + m \times \log m + n)$，空间复杂度 $O(l + m)$。其中 $l$ 和 $n$ 分别是数组 $logs$ 的长度和服务器的数量，而 $m$ 是数组 $queries$ 的长度。 + ### **Python3** @@ -62,7 +70,26 @@ ```python - +class Solution: + def countServers( + self, n: int, logs: List[List[int]], x: int, queries: List[int] + ) -> List[int]: + cnt = Counter() + logs.sort(key=lambda x: x[1]) + ans = [0] * len(queries) + j = k = 0 + for r, i in sorted(zip(queries, count())): + l = r - x + while k < len(logs) and logs[k][1] <= r: + cnt[logs[k][0]] += 1 + k += 1 + while j < len(logs) and logs[j][1] < l: + cnt[logs[j][0]] -= 1 + if cnt[logs[j][0]] == 0: + cnt.pop(logs[j][0]) + j += 1 + ans[i] = n - len(cnt) + return ans ``` ### **Java** @@ -70,19 +97,144 @@ ```java - +class Solution { + public int[] countServers(int n, int[][] logs, int x, int[] queries) { + Arrays.sort(logs, (a, b) -> a[1] - b[1]); + int m = queries.length; + int[][] qs = new int[m][0]; + for (int i = 0; i < m; ++i) { + qs[i] = new int[] {queries[i], i}; + } + Arrays.sort(qs, (a, b) -> a[0] - b[0]); + Map cnt = new HashMap<>(); + int[] ans = new int[m]; + int j = 0, k = 0; + for (var q : qs) { + int r = q[0], i = q[1]; + int l = r - x; + while (k < logs.length && logs[k][1] <= r) { + cnt.merge(logs[k++][0], 1, Integer::sum); + } + while (j < logs.length && logs[j][1] < l) { + if (cnt.merge(logs[j][0], -1, Integer::sum) == 0) { + cnt.remove(logs[j][0]); + } + j++; + } + ans[i] = n - cnt.size(); + } + return ans; + } +} ``` ### **C++** ```cpp - +class Solution { +public: + vector countServers(int n, vector>& logs, int x, vector& queries) { + sort(logs.begin(), logs.end(), [](const auto& a, const auto& b) { + return a[1] < b[1]; + }); + int m = queries.size(); + vector> qs(m); + for (int i = 0; i < m; ++i) { + qs[i] = {queries[i], i}; + } + sort(qs.begin(), qs.end()); + unordered_map cnt; + vector ans(m); + int j = 0, k = 0; + for (auto& [r, i] : qs) { + int l = r - x; + while (k < logs.size() && logs[k][1] <= r) { + ++cnt[logs[k++][0]]; + } + while (j < logs.size() && logs[j][1] < l) { + if (--cnt[logs[j][0]] == 0) { + cnt.erase(logs[j][0]); + } + ++j; + } + ans[i] = n - cnt.size(); + } + return ans; + } +}; ``` ### **Go** ```go +func countServers(n int, logs [][]int, x int, queries []int) []int { + sort.Slice(logs, func(i, j int) bool { return logs[i][1] < logs[j][1] }) + m := len(queries) + qs := make([][2]int, m) + for i, q := range queries { + qs[i] = [2]int{q, i} + } + sort.Slice(qs, func(i, j int) bool { return qs[i][0] < qs[j][0] }) + cnt := map[int]int{} + ans := make([]int, m) + j, k := 0, 0 + for _, q := range qs { + r, i := q[0], q[1] + l := r - x + for k < len(logs) && logs[k][1] <= r { + cnt[logs[k][0]]++ + k++ + } + for j < len(logs) && logs[j][1] < l { + cnt[logs[j][0]]-- + if cnt[logs[j][0]] == 0 { + delete(cnt, logs[j][0]) + } + j++ + } + ans[i] = n - len(cnt) + } + return ans +} +``` +### **TypeScript** + +```ts +function countServers( + n: number, + logs: number[][], + x: number, + queries: number[], +): number[] { + logs.sort((a, b) => a[1] - b[1]); + const m = queries.length; + const qs: number[][] = []; + for (let i = 0; i < m; ++i) { + qs.push([queries[i], i]); + } + qs.sort((a, b) => a[0] - b[0]); + const cnt: Map = new Map(); + const ans: number[] = new Array(m); + let j = 0; + let k = 0; + for (const [r, i] of qs) { + const l = r - x; + while (k < logs.length && logs[k][1] <= r) { + cnt.set(logs[k][0], (cnt.get(logs[k][0]) || 0) + 1); + ++k; + } + while (j < logs.length && logs[j][1] < l) { + cnt.set(logs[j][0], (cnt.get(logs[j][0]) || 0) - 1); + if (cnt.get(logs[j][0]) === 0) { + cnt.delete(logs[j][0]); + } + ++j; + } + ans[i] = n - cnt.size; + } + return ans; +} ``` ### **...** diff --git a/solution/2700-2799/2747.Count Zero Request Servers/README_EN.md b/solution/2700-2799/2747.Count Zero Request Servers/README_EN.md index 4254f7fc2d69f..b12ddd9b582ef 100644 --- a/solution/2700-2799/2747.Count Zero Request Servers/README_EN.md +++ b/solution/2700-2799/2747.Count Zero Request Servers/README_EN.md @@ -56,25 +56,169 @@ For queries[1]: Only server with id 3 gets no request in the duration [2,4]. ### **Python3** ```python - +class Solution: + def countServers( + self, n: int, logs: List[List[int]], x: int, queries: List[int] + ) -> List[int]: + cnt = Counter() + logs.sort(key=lambda x: x[1]) + ans = [0] * len(queries) + j = k = 0 + for r, i in sorted(zip(queries, count())): + l = r - x + while k < len(logs) and logs[k][1] <= r: + cnt[logs[k][0]] += 1 + k += 1 + while j < len(logs) and logs[j][1] < l: + cnt[logs[j][0]] -= 1 + if cnt[logs[j][0]] == 0: + cnt.pop(logs[j][0]) + j += 1 + ans[i] = n - len(cnt) + return ans ``` ### **Java** ```java - +class Solution { + public int[] countServers(int n, int[][] logs, int x, int[] queries) { + Arrays.sort(logs, (a, b) -> a[1] - b[1]); + int m = queries.length; + int[][] qs = new int[m][0]; + for (int i = 0; i < m; ++i) { + qs[i] = new int[] {queries[i], i}; + } + Arrays.sort(qs, (a, b) -> a[0] - b[0]); + Map cnt = new HashMap<>(); + int[] ans = new int[m]; + int j = 0, k = 0; + for (var q : qs) { + int r = q[0], i = q[1]; + int l = r - x; + while (k < logs.length && logs[k][1] <= r) { + cnt.merge(logs[k++][0], 1, Integer::sum); + } + while (j < logs.length && logs[j][1] < l) { + if (cnt.merge(logs[j][0], -1, Integer::sum) == 0) { + cnt.remove(logs[j][0]); + } + j++; + } + ans[i] = n - cnt.size(); + } + return ans; + } +} ``` ### **C++** ```cpp - +class Solution { +public: + vector countServers(int n, vector>& logs, int x, vector& queries) { + sort(logs.begin(), logs.end(), [](const auto& a, const auto& b) { + return a[1] < b[1]; + }); + int m = queries.size(); + vector> qs(m); + for (int i = 0; i < m; ++i) { + qs[i] = {queries[i], i}; + } + sort(qs.begin(), qs.end()); + unordered_map cnt; + vector ans(m); + int j = 0, k = 0; + for (auto& [r, i] : qs) { + int l = r - x; + while (k < logs.size() && logs[k][1] <= r) { + ++cnt[logs[k++][0]]; + } + while (j < logs.size() && logs[j][1] < l) { + if (--cnt[logs[j][0]] == 0) { + cnt.erase(logs[j][0]); + } + ++j; + } + ans[i] = n - cnt.size(); + } + return ans; + } +}; ``` ### **Go** ```go +func countServers(n int, logs [][]int, x int, queries []int) []int { + sort.Slice(logs, func(i, j int) bool { return logs[i][1] < logs[j][1] }) + m := len(queries) + qs := make([][2]int, m) + for i, q := range queries { + qs[i] = [2]int{q, i} + } + sort.Slice(qs, func(i, j int) bool { return qs[i][0] < qs[j][0] }) + cnt := map[int]int{} + ans := make([]int, m) + j, k := 0, 0 + for _, q := range qs { + r, i := q[0], q[1] + l := r - x + for k < len(logs) && logs[k][1] <= r { + cnt[logs[k][0]]++ + k++ + } + for j < len(logs) && logs[j][1] < l { + cnt[logs[j][0]]-- + if cnt[logs[j][0]] == 0 { + delete(cnt, logs[j][0]) + } + j++ + } + ans[i] = n - len(cnt) + } + return ans +} +``` +### **TypeScript** + +```ts +function countServers( + n: number, + logs: number[][], + x: number, + queries: number[], +): number[] { + logs.sort((a, b) => a[1] - b[1]); + const m = queries.length; + const qs: number[][] = []; + for (let i = 0; i < m; ++i) { + qs.push([queries[i], i]); + } + qs.sort((a, b) => a[0] - b[0]); + const cnt: Map = new Map(); + const ans: number[] = new Array(m); + let j = 0; + let k = 0; + for (const [r, i] of qs) { + const l = r - x; + while (k < logs.length && logs[k][1] <= r) { + cnt.set(logs[k][0], (cnt.get(logs[k][0]) || 0) + 1); + ++k; + } + while (j < logs.length && logs[j][1] < l) { + cnt.set(logs[j][0], (cnt.get(logs[j][0]) || 0) - 1); + if (cnt.get(logs[j][0]) === 0) { + cnt.delete(logs[j][0]); + } + ++j; + } + ans[i] = n - cnt.size; + } + return ans; +} ``` ### **...** diff --git a/solution/2700-2799/2747.Count Zero Request Servers/Solution.cpp b/solution/2700-2799/2747.Count Zero Request Servers/Solution.cpp new file mode 100644 index 0000000000000..a3ae297e6d836 --- /dev/null +++ b/solution/2700-2799/2747.Count Zero Request Servers/Solution.cpp @@ -0,0 +1,31 @@ +class Solution { +public: + vector countServers(int n, vector>& logs, int x, vector& queries) { + sort(logs.begin(), logs.end(), [](const auto& a, const auto& b) { + return a[1] < b[1]; + }); + int m = queries.size(); + vector> qs(m); + for (int i = 0; i < m; ++i) { + qs[i] = {queries[i], i}; + } + sort(qs.begin(), qs.end()); + unordered_map cnt; + vector ans(m); + int j = 0, k = 0; + for (auto& [r, i] : qs) { + int l = r - x; + while (k < logs.size() && logs[k][1] <= r) { + ++cnt[logs[k++][0]]; + } + while (j < logs.size() && logs[j][1] < l) { + if (--cnt[logs[j][0]] == 0) { + cnt.erase(logs[j][0]); + } + ++j; + } + ans[i] = n - cnt.size(); + } + return ans; + } +}; \ No newline at end of file diff --git a/solution/2700-2799/2747.Count Zero Request Servers/Solution.go b/solution/2700-2799/2747.Count Zero Request Servers/Solution.go new file mode 100644 index 0000000000000..3e86dcd2634d5 --- /dev/null +++ b/solution/2700-2799/2747.Count Zero Request Servers/Solution.go @@ -0,0 +1,29 @@ +func countServers(n int, logs [][]int, x int, queries []int) []int { + sort.Slice(logs, func(i, j int) bool { return logs[i][1] < logs[j][1] }) + m := len(queries) + qs := make([][2]int, m) + for i, q := range queries { + qs[i] = [2]int{q, i} + } + sort.Slice(qs, func(i, j int) bool { return qs[i][0] < qs[j][0] }) + cnt := map[int]int{} + ans := make([]int, m) + j, k := 0, 0 + for _, q := range qs { + r, i := q[0], q[1] + l := r - x + for k < len(logs) && logs[k][1] <= r { + cnt[logs[k][0]]++ + k++ + } + for j < len(logs) && logs[j][1] < l { + cnt[logs[j][0]]-- + if cnt[logs[j][0]] == 0 { + delete(cnt, logs[j][0]) + } + j++ + } + ans[i] = n - len(cnt) + } + return ans +} \ No newline at end of file diff --git a/solution/2700-2799/2747.Count Zero Request Servers/Solution.java b/solution/2700-2799/2747.Count Zero Request Servers/Solution.java new file mode 100644 index 0000000000000..ed5a7a4633035 --- /dev/null +++ b/solution/2700-2799/2747.Count Zero Request Servers/Solution.java @@ -0,0 +1,29 @@ +class Solution { + public int[] countServers(int n, int[][] logs, int x, int[] queries) { + Arrays.sort(logs, (a, b) -> a[1] - b[1]); + int m = queries.length; + int[][] qs = new int[m][0]; + for (int i = 0; i < m; ++i) { + qs[i] = new int[] {queries[i], i}; + } + Arrays.sort(qs, (a, b) -> a[0] - b[0]); + Map cnt = new HashMap<>(); + int[] ans = new int[m]; + int j = 0, k = 0; + for (var q : qs) { + int r = q[0], i = q[1]; + int l = r - x; + while (k < logs.length && logs[k][1] <= r) { + cnt.merge(logs[k++][0], 1, Integer::sum); + } + while (j < logs.length && logs[j][1] < l) { + if (cnt.merge(logs[j][0], -1, Integer::sum) == 0) { + cnt.remove(logs[j][0]); + } + j++; + } + ans[i] = n - cnt.size(); + } + return ans; + } +} \ No newline at end of file diff --git a/solution/2700-2799/2747.Count Zero Request Servers/Solution.py b/solution/2700-2799/2747.Count Zero Request Servers/Solution.py new file mode 100644 index 0000000000000..035b89655fad4 --- /dev/null +++ b/solution/2700-2799/2747.Count Zero Request Servers/Solution.py @@ -0,0 +1,20 @@ +class Solution: + def countServers( + self, n: int, logs: List[List[int]], x: int, queries: List[int] + ) -> List[int]: + cnt = Counter() + logs.sort(key=lambda x: x[1]) + ans = [0] * len(queries) + j = k = 0 + for r, i in sorted(zip(queries, count())): + l = r - x + while k < len(logs) and logs[k][1] <= r: + cnt[logs[k][0]] += 1 + k += 1 + while j < len(logs) and logs[j][1] < l: + cnt[logs[j][0]] -= 1 + if cnt[logs[j][0]] == 0: + cnt.pop(logs[j][0]) + j += 1 + ans[i] = n - len(cnt) + return ans diff --git a/solution/2700-2799/2747.Count Zero Request Servers/Solution.ts b/solution/2700-2799/2747.Count Zero Request Servers/Solution.ts new file mode 100644 index 0000000000000..978deb488c4da --- /dev/null +++ b/solution/2700-2799/2747.Count Zero Request Servers/Solution.ts @@ -0,0 +1,34 @@ +function countServers( + n: number, + logs: number[][], + x: number, + queries: number[], +): number[] { + logs.sort((a, b) => a[1] - b[1]); + const m = queries.length; + const qs: number[][] = []; + for (let i = 0; i < m; ++i) { + qs.push([queries[i], i]); + } + qs.sort((a, b) => a[0] - b[0]); + const cnt: Map = new Map(); + const ans: number[] = new Array(m); + let j = 0; + let k = 0; + for (const [r, i] of qs) { + const l = r - x; + while (k < logs.length && logs[k][1] <= r) { + cnt.set(logs[k][0], (cnt.get(logs[k][0]) || 0) + 1); + ++k; + } + while (j < logs.length && logs[j][1] < l) { + cnt.set(logs[j][0], (cnt.get(logs[j][0]) || 0) - 1); + if (cnt.get(logs[j][0]) === 0) { + cnt.delete(logs[j][0]); + } + ++j; + } + ans[i] = n - cnt.size; + } + return ans; +}