half of 4th seminar

seminar04_templates/03_factorization/main.cpp

@@ -0,0 +1,74 @@
+#include <iostream>
+#include <utility>
+#include <vector>
+#include <cmath>
+
+using std::cout, std::endl, std::pair, std::vector;
+
+int next_prime(int n);
+
+vector<pair<int, int>> factorization(int n) {
+    if (n == 1) {
+        return vector<pair<int,int>>{{1, 1}};
+    }
+    int d = 2;
+    int c;
+    vector<pair<int, int>> result;
+    
+    while(n != 1) {
+        c = 0;
+        while(n % d == 0) {
+            c++;
+            n /= d;
+        }
+        if (c)
+            result.push_back(pair{d, c});
+        d = next_prime(d);
+    }
+    return result;
+}
+
+bool is_prime(int n) {
+    bool prime = true;
+    for(int i = 2; i <= static_cast<int>(std::sqrt(n)); i++) {
+        if (n % i == 0) {
+            prime = false;
+            break;
+        }
+    }
+    return prime;
+}
+
+int next_prime(int n) {
+    ++n;
+    while (true) {
+        if (is_prime(n))
+                return n;
+        ++n;
+    }
+}
+
+std::ostream& operator<<(std::ostream& out, pair<int,int> p) {
+    out << "{" << p.first << ", " << p.second << "}";
+    return out;
+}
+
+std::ostream& operator<<(std::ostream& out, vector<pair<int,int>> v) {
+    out << "{";
+    size_t size = v.size();
+    for(int i = 0; i < size; ++i) {
+        out << v[i] << (i == size - 1 ? "}" : ", ");
+    }
+    return out;
+}
+
+int main() {
+        vector<pair<int, int>> res = factorization(60);
+        cout << res << endl;
+        res = factorization(626215995);
+        cout << res << endl;
+        res = factorization(107);
+        cout << res << endl;
+        res = factorization(1);
+        cout << res << endl;
+}