add task4

task4.cpp

@@ -0,0 +1,75 @@
+#include <iostream>
+#include <fstream>
+#include <cstring>
+#include <cctype>
+
+using namespace std;
+
+int main() 
+{
+    setlocale(LC_ALL, "Russian");
+
+    // Øàã 1: Çàïðîñ ó ïîëüçîâàòåëÿ èìÿ ôàéëà
+    char filename[256];
+    cout << "Ââåäèòå èìÿ ôàéëà: ";
+    cin.getline(filename, sizeof(filename));
+
+    // Øàã 2: Ïðîâåðêà êîððåêòíîñòè èìåíè ôàéëà
+    bool isValid = true;
+
+    // Ïðîâåðêà íà çàïðåùåííûå ñèìâîëû
+    const char* forbiddenChars = "*\"<>?|";
+    if (strpbrk(filename, forbiddenChars) != nullptr)
+        isValid = false;
+
+    // Ïðîâåðêà íà äâîåòî÷èå
+    if (strchr(filename, ':') != nullptr && 
+        (filename[1] != '\\' || !isalpha(filename[0]) || 
+        strchr(filename, '\\') != strrchr(filename, '\\')))
+        isValid = false;
+
+    // Øàã 3: Ïðîâåðêà íà ðàñøèðåíèå
+    const char* extension = ".txt";
+    if (strncmp(strrchr(filename, '.'), extension, strlen(extension)) != 0)
+        strcat(filename, extension);
+
+    // Øàã 4: Çàãðóçèòü ñîäåðæèìîå òåêñòîâîãî ôàéëà â ïàìÿòü
+    if (isValid) 
+    {
+        ifstream file(filename, ios::binary | ios::ate);
+        if (file.is_open()) 
+        {
+            streampos fileSize = file.tellg();
+            char* buffer = new char[fileSize];
+            file.seekg(0, ios::beg);
+            file.read(buffer, fileSize);
+            file.close();
+
+            // Øàã 5: Çàïðîñèòü ó ïîëüçîâàòåëÿ ñòðîêó
+            char searchString[256];
+            cout << "Ââåäèòå ñòðîêó äëÿ ïîèñêà: ";
+            cin.getline(searchString, sizeof(searchString));
+
+            // Øàã 6: Ïîäñ÷èòàòü ÷èñëî âõîæäåíèé ñòðîêè â òåêñò ôàéë
+            int count = 0;
+            char* p = buffer;
+            while ((p = strstr(p, searchString)) != nullptr) 
+            {
+                count++;
+                p += strlen(searchString);
+            }
+
+            cout << "×èñëî âõîæäåíèé ñòðîêè \"" << searchString << "\" â òåêñòîâîì ôàéëå: " << count << endl;
+
+            // Øàã 7: Îñâîáîäèòü âûäåëåííóþ ïàìÿòü
+            delete[] buffer;
+        }
+        else 
+            cout << "Îøèáêà îòêðûòèÿ ôàéëà." << endl;
+    }
+    else 
+        cout << "Íåêîððåêòíîå èìÿ ôàéëà." << endl;
+
+    system("pause");
+    return 0;
+}

text.txt

@@ -0,0 +1,2 @@
+I am a programmist!!!
+This program is working so good!