KMP模板

inline void BuildNext(char pattern[], int length, int next[])
{
    int i, t;
    i = 1;
    t = 0;
    next[1] = 0;
    while(i < length + 1)
    {
        while(t > 0 && pattern[i - 1] != pattern[t - 1])
        {
            t = next[t];
        }
        ++t;
        ++i;
        if(pattern[i - 1] == pattern[t - 1])
        {
            next[i] = next[t];
        }
        else
        {
            next[i] = t;
        }
    }
    //pattern末尾的结束符控制，用于寻找目标字符串中的所有匹配结果用
    while(t > 0 && pattern[i - 1] != pattern[t - 1])
    {
        t = next[t];
    }
    ++t;
    ++i;
    next[i] = t;
}
int KMP(char text[], int text_length, char pattern[], int  pattern_length,int matches[],bool mark[])
{
    int i, j, n;
    int next[pattern_length + 2];
    BuildNext(pattern, pattern_length, next);
    i = 0;
    j = 1;
    n = 0;
    while(pattern_length + 1 - j <= text_length - i)
    {
        if(text[i] == pattern[j - 1])
        {
            ++i;
            ++j;
            //发现匹配结果，将匹配子串的位置，加入结果
            if(j == pattern_length + 1)
            {
                matches[n++] = i - pattern_length;
                j = next[j];
            }
        }
        else
        {
            j = next[j];
            if(j == 0)
            {
                ++i;
                ++j;
            }
        }
    }
    return n;
}