字符串匹配

/* 字符串匹配:> BM->KMP */
int func(char*s, char*p)
{
    int i = 0;
    int j = 0;
    while (i < strlen(s))
    {
        j = 0;
        while (s[i] == p[j] && j < strlen(p))
        {
            j++;
            i++;
        }
        if (j == strlen(p))
            return i - j;
        i = i - j + 1;
    }
    return -1;
}

void getNext(char*p, int *next)
{
    next[0] = -1;
    int slow = -1;
    int fast = 0;

    while (fast < strlen(p) - 1)
    {
        if (slow == -1 || p[slow] == p[fast])
        {
            slow++;
            fast++;

            next[fast] = slow;
        }
        else
            slow = next[slow];
    }
}

int KMP(char*s, char*p)
{
    int next[100];
    int i = 0;
    int j = 0;
    getNext(p, next);

    while (i < strlen(s))
    {
        if (j == -1 || s[i] == p[j])
        {
            ++i;
            ++j;
        }
        else
        {
            j = next[j];
        }
        if (j == strlen(p))
            return i - strlen(p);

    }
    return -1;
}

关于next数组和KMP参见链接：
http://note.youdao.com/share/?id=f9906cb0d53a384435d83d66b59fafa5&type=note

http://note.youdao.com/share/?id=2312592fd636b64f270d18240dbb0268&type=note