docs update

README.md

@@ -143,10 +143,11 @@ Performance results for cpython 3.9 are applicable to for pkpy.
 
 See https://pocketpy.dev/performance/ for details.
 
-And these are the results of the primes benchmark on Intel i5-12400F, WSL (Ubuntu 20.04 LTS), which *roughly* reflects the performance among lua, pkpy and cpython.
+And these are the results of the primes benchmark on Intel i5-12400F, WSL (Ubuntu 20.04 LTS), which *roughly* reflects the performance among c++, lua, pkpy and cpython.
 
 | name | version | time | file |
 | ---- | ---- | ---- | ---- |
+| c++ | gnu++11 | `0.104s ■□□□□□□□□□□□□□□□` | [benchmarks/primes.cpp](https://github.com/blueloveTH/pocketpy/blob/3d332a694f99ae2d327e732e7f3e3215bedcb069/benchmarks/primes.cpp) |
 | lua | 5.3.3 | `1.576s ■■■■■■■■■□□□□□□□` | [benchmarks/primes.lua](https://github.com/blueloveTH/pocketpy/blob/3d332a694f99ae2d327e732e7f3e3215bedcb069/benchmarks/primes.lua) |
 | pkpy | 1.2.7 | `2.385s ■■■■■■■■■■■■■□□□` | [benchmarks/primes.py](https://github.com/blueloveTH/pocketpy/blob/3d332a694f99ae2d327e732e7f3e3215bedcb069/benchmarks/primes.py) |
 | cpython | 3.8.10 | `2.871s ■■■■■■■■■■■■■■■■` | [benchmarks/primes.py](https://github.com/blueloveTH/pocketpy/blob/3d332a694f99ae2d327e732e7f3e3215bedcb069/benchmarks/primes.py) |

benchmarks/primes.cpp

@@ -0,0 +1,167 @@
+#include <vector>
+#include <string>
+#include <queue>
+#include <iostream>
+#include <algorithm>
+#include <unordered_map>
+
+typedef long long LL;
+
+struct Node{
+    std::unordered_map<int, Node*> children;
+    bool terminal;
+
+    Node(){
+        terminal = false;
+    }
+};
+
+struct Sieve{
+    LL limit;
+    std::vector<bool> prime;
+
+    Sieve(LL limit){
+        this->limit = limit;
+        prime = std::vector<bool>(limit + 1, false);
+    }
+
+    std::vector<LL> to_list(){
+        std::vector<LL> result;
+        result.push_back(2);
+        result.push_back(3);
+        for(LL p = 5; p <= limit; p++){
+            if(prime[p]){
+                result.push_back(p);
+            }
+        }
+        return result;
+    }
+
+    void omit_squares(){
+        LL r = 5;
+        while(r * r < limit){
+            if(prime[r]){
+                LL i = r * r;
+                while(i < limit){
+                    prime[i] = false;
+                    i = i + r * r;
+                }
+            }
+            r += 1;
+        }
+    }
+
+    void step1(LL x, LL y){
+        LL n = (4 * x * x) + (y * y);
+        if(n <= limit && (n % 12 == 1 || n % 12 == 5)){
+            prime[n] = !prime[n];
+        }
+    }
+
+    void step2(LL x, LL y){
+        LL n = (3 * x * x) + (y * y);
+        if(n <= limit && n % 12 == 7){
+            prime[n] = !prime[n];
+        }
+    }
+
+    void step3(LL x, LL y){
+        LL n = (3 * x * x) - (y * y);
+        if(x > y && n <= limit && n % 12 == 11){
+            prime[n] = !prime[n];
+        }
+    }
+
+    void loop_y(LL x){
+        LL y = 1;
+        while(y * y < limit){
+            step1(x, y);
+            step2(x, y);
+            step3(x, y);
+            y += 1;
+        }
+    }
+
+    void loop_x(){
+        LL x = 1;
+        while(x * x < limit){
+            loop_y(x);
+            x += 1;
+        }
+    }
+
+    void calc(){
+        loop_x();
+        omit_squares();
+    }
+};
+
+Node *generate_trie(std::vector<LL> l){
+    Node *root = new Node();
+    for(LL el : l){
+        Node *head = root;
+        std::string s = std::to_string(el);
+        for(char ch : s){
+            if(head->children.find(ch) == head->children.end()){
+                head->children[ch] = new Node();
+            }
+            head = head->children[ch];
+        }
+        head->terminal = true;
+    }
+    return root;
+}
+
+std::vector<LL> find(LL upper_bound, LL prefix){
+    Sieve *sieve = new Sieve(upper_bound);
+    sieve->calc();
+    std::string str_prefix = std::to_string(prefix);
+    Node *head = generate_trie(sieve->to_list());
+    for(char ch : str_prefix){
+        if(head->children.find(ch) == head->children.end()){
+            return std::vector<LL>();
+        }
+        head = head->children[ch];
+    }
+
+    std::queue<std::pair<Node*, std::string>> q;
+    std::vector<LL> result;
+    q.push(std::make_pair(head, str_prefix));
+    while(!q.empty()){
+        std::pair<Node*, std::string> top = q.front();
+        q.pop();
+        if(top.first->terminal){
+            result.push_back(std::stoll(top.second));
+        }
+        for(std::pair<char, Node*> p : top.first->children){
+            q.push(std::make_pair(p.second, top.second + p.first));
+        }
+    }
+
+    std::sort(result.begin(), result.end());
+    return result;
+}
+
+void verify(){
+    std::vector<LL> left = {2, 23, 29};
+    std::vector<LL> right = find(100, 2);
+    if(left != right){
+        std::cout << "left != right" << std::endl;
+        exit(1);
+    }
+}
+
+
+int main(){
+    const LL UPPER_BOUND = 5000000;
+    const LL PREFIX = 32338;
+
+    verify();
+    std::vector<LL> results = find(UPPER_BOUND, PREFIX);
+    std::vector<LL> expected = {323381, 323383, 3233803, 3233809, 3233851, 3233863, 3233873, 3233887, 3233897};
+    if(results != expected){
+        std::cout << "results != expected" << std::endl;
+        exit(1);
+    }
+    return 0;
+}

docs/performance.md

@@ -134,6 +134,7 @@ These are the results of the primes benchmark on Intel i5-12400F, WSL (Ubuntu 20
 
 | name | version | time | file |
 | ---- | ---- | ---- | ---- |
+| c++ | gnu++11 | `0.104s ■□□□□□□□□□□□□□□□` | [benchmarks/primes.cpp](https://github.com/blueloveTH/pocketpy/blob/3d332a694f99ae2d327e732e7f3e3215bedcb069/benchmarks/primes.cpp) |
 | lua | 5.3.3 | `1.576s ■■■■■■■■■□□□□□□□` | [benchmarks/primes.lua](https://github.com/blueloveTH/pocketpy/blob/3d332a694f99ae2d327e732e7f3e3215bedcb069/benchmarks/primes.lua) |
 | pkpy | 1.2.7 | `2.385s ■■■■■■■■■■■■■□□□` | [benchmarks/primes.py](https://github.com/blueloveTH/pocketpy/blob/3d332a694f99ae2d327e732e7f3e3215bedcb069/benchmarks/primes.py) |
 | cpython | 3.8.10 | `2.871s ■■■■■■■■■■■■■■■■` | [benchmarks/primes.py](https://github.com/blueloveTH/pocketpy/blob/3d332a694f99ae2d327e732e7f3e3215bedcb069/benchmarks/primes.py) |