【字符串】KMP匹配模板

char str1[1010];
char str2[1010];
int Next[1010];

void next_arr()
{
    int len = strlen(str2);
    Next[0] = -1;
    int k = -1;
    int j = 0;
    while (j < len - 1)//这个减一好像写不写都行，我看被人都没写
    {
        if (k == -1 || str2[j] == str2[k])
        {
            ++k;
            ++j;
            Next[j] = k;
        }
        else
            k = Next[k];
    }
}

int kmp_match()
{
    next_arr();
    int i=0,j=0;
    int len1=strlen(str1);
    int len2=strlen(str2);
    while(i

求子串个数

char str1[1000008];
char str2[1000008];
int Next[1000008];
int ans;

void next_arr(){
    int len = strlen(str2);
    Next[0] = -1;
    int k = -1;
    int j = 0;
    while (j < len)//这里改了
    {
        if (k == -1 || str2[j] == str2[k])
        {
            ++k;
            ++j;
            Next[j] = k;
        }
        else
            k = Next[k];
    }
}
 
int kmp_match(){
    next_arr();
    int i=0,j=0;
    int len1=strlen(str1);
    int len2=strlen(str2);
    while(i