move shii

lab_1/12_first_symbols_to_spaces.cpp

@@ -1,3 +1,72 @@
-//
+// Task 12 (Ubuntu): replace every char equal to the first char of its line with a space.
-// Created by pajjilykk on 10/1/25.
+// Usage: ./task12 <input_file>  → writes "<input_file>.out" and prints replacement count.
-//
+
+#include <iostream>
+#include <fstream>
+#include <string>
+#include <sys/stat.h>
+
+// True if file exists (POSIX stat)
+static bool file_exists(const std::string &path) {
+    struct stat st{};
+    return ::stat(path.c_str(), &st) == 0;
+}
+
+// "<name>.out" by replacing last extension or appending if none
+static std::string make_out_name(const std::string &in) {
+    std::size_t pos = in.find_last_of('.');
+    if (pos == std::string::npos) return in + ".out";
+    return in.substr(0, pos) + ".out";
+}
+
+int main(int argc, char *argv[]) {
+    if (argc != 2) {
+        std::cerr << "Usage: " << argv[0] << " <input_file>\n";
+        return -1;
+    }
+
+    std::string in_path = argv[1];
+    if (!file_exists(in_path)) {
+        std::cerr << "Error: input file does not exist.\n";
+        return -1;
+    }
+
+    std::ifstream in(in_path);
+    if (!in) {
+        std::cerr << "Error: cannot open input file.\n";
+        return -1;
+    }
+
+    std::string out_path = make_out_name(in_path);
+    std::ofstream out(out_path);
+    if (!out) {
+        std::cerr << "Error: cannot create output file.\n";
+        return -1;
+    }
+
+    long long replacements = 0;
+    std::string line;
+
+    while (std::getline(in, line)) {
+        if (!line.empty()) {
+            char first = line.front();
+            for (char &c: line) {
+                if (c == first) {
+                    if (c != ' ') {
+                        c = ' ';
+                        ++replacements;
+                    } // count only real changes
+                }
+            }
+        }
+        out << line;
+        if (!in.eof()) out << '\n';
+        if (!out) {
+            std::cerr << "Error: write error.\n";
+            return -1;
+        }
+    }
+
+    std::cout << replacements << std::endl;
+    return static_cast<int>(replacements);
+}

lab_1/compile.sh

@@ -0,0 +1 @@
+g++ -std=c++17 -O2 -Wall -Wextra 12_first_symbols_to_spaces.cpp -o 12_first_symbols_to_spaces

lab_1/file.in

@@ -0,0 +1,8 @@
+abcabcABC
+Aaaaaa
+1112233111
+,,,,.,,
+leading spaces here
+tab leading here
+first-letter f repeats: f fff f-f_f
+ZzzZzZ

lab_1/run.sh

@@ -0,0 +1 @@
+./12_first_symbols_to_spaces file.in