LearningCPP/main.cpp

#include <string>
#include <vector>
#include <thread>
#include <iostream>
#include <atomic>

using atomic_bool = std::atomic_bool;
using thread = std::thread;
using string = std::string;
using svector = std::vector<string>;
using tvector = std::vector<thread>;

void exec_containsSubstring(string&,string&,int,int, atomic_bool&);
bool containsSubstring(string&,string&,int,int);
string prompts(const string&,bool*);
int prompti(const string&,bool*);

int main() {
    tvector threads;
    svector inputs;
    bool s{};
    int numt = prompti("Enter the number of threads for searching: ", &s);
    if (!s)
        return 0;
    if (numt < 1) {
        std::cout << "Invalid Thread Count!\n";
        return 1;
    }
    string toTest = prompts("Enter the string to search in: ", &s);
    if (!s)
        return 0;
    if (static_cast<int>(toTest.length())/numt == 0) {
        std::cout << "Invalid Search String Length!\n";
        return 1;
    }
    string testFor = prompts("Enter the string to search for: ", &s);
    if (!s)
        return 0;
    if (testFor.length() == 0 || testFor.length() > toTest.length()) {
        std::cout << "Invalid Searching String Length!\n";
        return 1;
    }
    atomic_bool res{false};
    for (int i = 0; i < numt; ++i)
        threads.push_back(thread {exec_containsSubstring, std::ref(toTest), std::ref(testFor), i*static_cast<int>(toTest.length())/numt, (i+1)*static_cast<int>(toTest.length())/numt, std::ref(res)});
    for (auto &t : threads)
        t.join();
    std::cout << "String Contained state: " << res.load() << "\n" << std::flush;
    return 0;

}

void exec_containsSubstring(string& toTest,string& testFor, int startIndex, int endIndex, atomic_bool& res) {
    bool hm {containsSubstring(toTest,testFor, startIndex, endIndex)};
    if (hm)
        res.store(hm);
}

bool containsSubstring(string& toTest,string& testFor, int startIndex, int endIndex) {
    bool matches {true};
    while (startIndex < endIndex && startIndex < static_cast<int>(toTest.length())) {
        for (int i = 0; i < static_cast<int>(testFor.length()); ++i) {
            matches &= toTest[(long long unsigned int)(i+startIndex)] == testFor[(long long unsigned int)i];
            if (!matches)
                break;
        }
        if (matches)
            return true;
        matches = true;
        ++startIndex;
    }
    return false;
}

string prompts(const string &message, bool *success) {
    string tr{""};
    *success = false;
    std::cout << message;
    if (!(std::getline(std::cin,tr))) {
        std::cin.clear();
        std::cin.ignore();
        return "";
    }
    *success = true;
    return tr;
}

int prompti(const string &message, bool *success) {
    int tr{0};
    *success = false;
    std::cout << message;
    if (!(std::cin >> tr)) {
        std::cin.clear();
        std::cin.ignore();
        return 0;
    }
    *success = true;
    std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
    return tr;
}