1#include <stdio.h>
2#include <string.h>
3#include <stdlib.h>
4#include <ctype.h>
5
6#define MAX_WORD_LENGTH 100
7#define MAX_PARAGRAPH_LENGTH 1000
8
9typedef struct {
10    char word[MAX_WORD_LENGTH];
11    int count;
12} WordFrequency;
13
14int isBanned(const char* word, const char** banned, int bannedSize) {
15    for (int i = 0; i < bannedSize; i++) {
16        if (strcmp(word, banned[i]) == 0) {
17            return 1;
18        }
19    }
20    return 0;
21}
22
23char* mostCommonWord(char* paragraph, const char** banned, int bannedSize) {
24    WordFrequency wordFreq[MAX_PARAGRAPH_LENGTH] = {0};
25    char* result = NULL;
26    int maxCount = 0;
27    int wordFreqSize = 0;
28    char delimiters[] = " !?',;.",
29         *token = strtok(paragraph, delimiters);
30
31    while (token != NULL) {
32        char word[MAX_WORD_LENGTH];
33        strcpy(word, token);
34        for (int i = 0; word[i]; i++) {
35            word[i] = tolower(word[i]);
36        }
37        if (!isBanned(word, banned, bannedSize)) {
38            int found = 0;
39            for (int i = 0; i < wordFreqSize; i++) {
40                if (strcmp(wordFreq[i].word, word) == 0) {
41                    wordFreq[i].count++;
42                    found = 1;
43                    break; 
44                }
45            }
46            if (!found) {
47                strcpy(wordFreq[wordFreqSize].word, word);
48                wordFreq[wordFreqSize].count = 1;
49                wordFreqSize++;
50            }
51        }
52        token = strtok(NULL, delimiters);
53    }
54
55    for (int i = 0; i < wordFreqSize; i++) {
56        if (wordFreq[i].count > maxCount) {
57            maxCount = wordFreq[i].count;
58            result = wordFreq[i].word;
59        }
60    }
61    return result;
62}
63
64int main() {
65    const char* banned[] = {"hit"};
66    char paragraph[] = "Bob hit a ball, the hit BALL flew far after it was hit.";
67    printf("%s\n", mostCommonWord(paragraph, banned, 1));
68    return 0;
69}

1function