// Optimal approach using hash table and qsort
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <regex.h>

#define MAX_TWEETS 1000
#define MAX_HASHTAGS 100
#define MAX_HASHTAG_LEN 50

typedef struct {
    int user_id, tweet_id;
    char tweet_date[12];
    char tweet[256];
} Tweet;

typedef struct {
    char hashtag[MAX_HASHTAG_LEN];
    int count;
} HashtagCount;

// Comparison function for qsort
int compareHashtags(const void* a, const void* b) {
    const HashtagCount* hcA = (const HashtagCount*)a;
    const HashtagCount* hcB = (const HashtagCount*)b;
    
    if (hcA->count != hcB->count) {
        return hcB->count - hcA->count; // Descending by count
    }
    return strcmp(hcB->hashtag, hcA->hashtag); // Descending by hashtag
}

// Extract hashtag from tweet text
int extractHashtag(const char* tweet, char* hashtag) {
    const char* hashPos = strchr(tweet, '#');
    if (!hashPos) return 0;
    
    int i = 0;
    while (hashPos[i] && hashPos[i] != ' ' && i < MAX_HASHTAG_LEN - 1) {
        hashtag[i] = hashPos[i];
        i++;
    }
    hashtag[i] = '\0';
    return i > 1; // Return 1 if valid hashtag found
}

void findTrendingHashtags() {
    // Sample tweets
    Tweet tweets[] = {
        {1, 1, "2024-02-01", "Beautiful morning! #sunny"},
        {2, 2, "2024-02-02", "Working remotely today #remote"},
        {3, 3, "2024-02-03", "Another sunny day! #sunny"},
        {4, 4, "2024-02-04", "Love working from home #remote"},
        {5, 5, "2024-02-05", "Valentine preparation #love"},
        {6, 6, "2024-01-30", "This should not appear #winter"}
    };
    int tweetCount = sizeof(tweets) / sizeof(tweets[0]);
    
    HashtagCount hashtagCounts[MAX_HASHTAGS];
    int uniqueCount = 0;
    
    // One pass: filter February tweets and count hashtags
    for (int i = 0; i < tweetCount; i++) {
        if (strstr(tweets[i].tweet_date, "2024-02") != NULL) {
            char hashtag[MAX_HASHTAG_LEN];
            if (extractHashtag(tweets[i].tweet, hashtag)) {
                // Find existing hashtag or add new one
                int found = 0;
                for (int j = 0; j < uniqueCount; j++) {
                    if (strcmp(hashtagCounts[j].hashtag, hashtag) == 0) {
                        hashtagCounts[j].count++;
                        found = 1;
                        break;
                    }
                }
                if (!found && uniqueCount < MAX_HASHTAGS) {
                    strcpy(hashtagCounts[uniqueCount].hashtag, hashtag);
                    hashtagCounts[uniqueCount].count = 1;
                    uniqueCount++;
                }
            }
        }
    }
    
    // Sort hashtags
    qsort(hashtagCounts, uniqueCount, sizeof(HashtagCount), compareHashtags);
    
    // Print top 3
    int limit = uniqueCount < 3 ? uniqueCount : 3;
    for (int i = 0; i < limit; i++) {
        printf("%s: %d\n", hashtagCounts[i].hashtag, hashtagCounts[i].count);
    }
}

int main() {
    findTrendingHashtags();
    return 0;
}