logrecent.cpp

#include <iostream>
#include <fstream>
#include <string>

using namespace std;

class LogProcessor {
    struct User {
        string userId;
        string timestamp;
    };

    User* users;
    int size;

    struct Latest {
        string userId;
        string timestamp;
    };

    Latest* latestUsers;
    int latestCount;

public:
    LogProcessor() {
        size = 1000;
        users = new User[size];
        latestUsers = new Latest[1000];
        latestCount = 0;
    }

    void readLogFile(const string& filename) {
        ifstream file(filename);
        string uid, ts;
        int index = 0;

        while (file >> uid >> ts) {
            users[index].userId = uid;
            users[index].timestamp = ts;
            index++;
        }
        size = index;
        file.close();
    }

    bool isNewer(string t1, string t2) {
        return t1 > t2; // ISO format strings can be compared lexicographically
    }

    void processLatest() {
        for (int i = 0; i < size; i++) {
            bool found = false;
            for (int j = 0; j < latestCount; j++) {
                if (users[i].userId == latestUsers[j].userId) {
                    found = true;
                    if (isNewer(users[i].timestamp, latestUsers[j].timestamp)) {
                        latestUsers[j].timestamp = users[i].timestamp;
                    }
                    break;
                }
            }
            if (!found) {
                latestUsers[latestCount].userId = users[i].userId;
                latestUsers[latestCount].timestamp = users[i].timestamp;
                latestCount++;
            }
        }
    }

    void sortLatest() {
        for (int i = 0; i < latestCount - 1; i++) {
            for (int j = i + 1; j < latestCount; j++) {
                if (isNewer(latestUsers[j].timestamp, latestUsers[i].timestamp)) {
                    Latest temp = latestUsers[i];
                    latestUsers[i] = latestUsers[j];
                    latestUsers[j] = temp;
                }
            }
        }
    }

    void displayTopFive() {
        cout << "Top 5 most recently active users:\n";
        for (int i = 0; i < 5 && i < latestCount; i++) {
            cout << latestUsers[i].userId << " " << latestUsers[i].timestamp << endl;
        }
    }

    ~LogProcessor() {
        delete[] users;
        delete[] latestUsers;
    }
};

int main() {
    LogProcessor lp;
    lp.readLogFile("log.txt");
    lp.processLatest();
    lp.sortLatest();
    lp.displayTopFive();
    return 0;
}