c语言练习：统计词频

Question

统计w指向的数组中的2个单词在a指向的字符串中各自出现的次数(将非字母字符看做单词分隔符)
样例输入：this is a book,that is an apple
样例输出：this:1 is:2
我写的代码出不来结果，求改正讲解

#include<stdio.h>
#include<string.h>
#include <stdlib.h>

void count(char a[], char w[][10])
{
    int i;
    int k;
    int j;
    int len1=0,len2=0,time=0,count1,count2;
    
    count1=0;
    count2=0;
    for(i=0;a[i]!='\0';i++)
    {
        if((a[i]>='a'&&a[i]<='z')||(a[i]>='A'&&a[i]<='Z'))
            k=0;
        else
            break;
    }
    
    strncpy(w[0],a,i);
    w[0][i]='\0';
    for(j=i+1;a[j]!='\0';i++)
    {
        if((a[j]>='a'&&a[j]<='z')||(a[j]>='A'&&a[j]<='Z'))
            k=0;
        else
            break;
    }
    strncpy(w[1],a+i+1,j-i-1);
    w[1][j-i-1]='\0';//改动2
    //i是第一个单词的长度，j-i-1是第二个单词的长度
    len1=i;
    len2=j-i-1;
    for(i=0;a[i]!=0;i++)
    {
        for(j=0;j<2;j++)
        {
            k=0;
            if(a[i]==w[j][0])
            {
                for(i=i+1,k=1,time=1;k<len1;i++,k++)
                {
                    if(a[i]==w[j][k])
                    {
                        time++;
                    }
                }
                if(time==len1)
                {
                    count1++;
                }
            }
        }
    }

    for(i=0;a[i]!=0;i++)
    {
        for(j=0;j<2;j++)
        {
            k=0;
            if(a[i]==w[j][1])
            {
                for(i=i+1,k=1,time=1;k<len2;i++,k++)
                {
                    if(a[i]==w[j][k])
                    {
                        time++;
                    }
                }
                if(time==len2)
                {
                    count2++;
                }
            }
        }
    }
    printf("%s:%d",w[0],count1);
    printf("%s:%d",w[1],count2);
}

int main(void)
{
    char a[100];
    char w[2][10];
    

    fgets(a,100,stdin);
    //scanf("%s",a);
    a[strcspn(a, "\n")] = '\0';
    count(a,w);
    printf("\n%s",a);
    return 0;
}

Answer 1

#include <stdio.h>
#include <string.h>
#include <ctype.h>

void count(char* a, char w[][10])
{
    int count1 = 0;
    int count2 = 0;

    char* word = strtok(a, " ");
    while (word != NULL) {
        if (strcmp(word, w[0]) == 0) {
            count1++;
        }

        if (strcmp(word, w[1]) == 0) {
            count2++;
        }

        word = strtok(NULL, " ");
    }

    printf("%s:%d %s:%d\n", w[0], count1, w[1], count2);
}

int main(void)
{
    char a[100];
    char w[2][10];

    fgets(a, 100, stdin);
    a[strcspn(a, "\n")] = '\0';

    sscanf(a, "%s %s", w[0], w[1]);

    count(a, w);
    return 0;
}