从一篇文章中检查特定单词出现数量和第一次出现位置

#include<stdio.h>

int strlen(char*);
void changeLaggerToSmaller(char*);

int main(void)
{
    char word[15], content[1024*1024];
    int discovedCnt=0, firstPos= -1;
    int i,j,k;

    scanf("%s", word);
    getchar();
    gets(content);

    changeLaggerToSmaller(word);
    changeLaggerToSmaller(content);

    i=0;
    j=0;
    while (content[i] != '')
    {
        do
        {
            if(word[j] == '' || word[j] != content[i+j])
            {
                k=j;
                j=0;
                break;
            }
            j++;
        }
        while(word[j] != '');

        if(j>0)
        {
            discovedCnt++;
            if(firstPos<0)
                firstPos=i;
            i+=k;
        }
        i++;
    }

    printf("discoved count: %d
first position: %d
", discovedCnt, firstPos-strlen(word));
    return 0;
}

int strlen(char *pointer)
{
    int length=0;
    while(*pointer != '')
        pointer++;
    return length;
}

void changeLaggerToSmaller(char *pointer)
{
    while (*pointer != '')
    {
        if (*pointer >= 'A' && *pointer <= 'Z')
            *pointer = *pointer + 32;
        pointer++;
    }
}

第一个输入是单词 ，第二个输入是文章 ，回车执行控制台读取。