字符串哈希初步 洛谷3370

跑得好慢QAQ

#include<cstdio>#include<cctype>#include<cstring>using namespace std;inline void read(int &x){    x = 0;    int flag = 1;    char c;    while(! isgraph(c = getchar()))        if(c == '-')            c = getchar();    while(isgraph(c))        x = x * 10 + c - '0', c = getchar();    x *= flag;}inline void read(char *s){    char c;    while(! isgraph(c = getchar()));    int top = 0;    while(isgraph(c))        *(s + (top ++)) = c, c = getchar();}const int MAXN = 1 << 14;const int MAXLEN = 1 << 11;int top;int head[1 << 20];int hash(char *s){    int len = strlen(s);    unsigned int h = 0;    for(int i = 0; i < len; i ++)        h = h * 31 + *(s + i);    return h & 0x7fffffff;}struct Table{    char s[MAXLEN];    int next;}table[MAXN];void print(int x){    if(x == 0)        putchar('0');    int ans[1 << 4], top = 0;    while(x)        ans[top ++] = x % 10, x /= 10;    for(; top; top --)        putchar(ans[top - 1] + '0');    putchar('\n');}int main(){    int n;    read(n);    int top = 0;    memset(head, - 1, sizeof(head));    int ans = 0;    char s[MAXLEN];    memset(s, 0, sizeof(s));    for(int i = 0; i < n; i ++)    {        read(s);        int len = strlen(s);//        int ha = hash(s) % (1 << 20);        int ha = 1;        int j = head[ha];        while(1)        {            if(j == - 1)            {                for(int k = 0; k < len; k ++)                    table[top].s[k] = s[k];                table[top].next = head[ha];                head[ha] = top ++;                ans ++;                break;            }            else if (len == strlen(table[j].s))            {                int flag = 1;                for(int k = 0; k < len; k ++)                    if(table[j].s[k] != s[k])                        flag = 0;                if(flag)                    break;            }            j = table[j].next;        }        for(int i = 0; i < len; i ++)            s[i] = 0;    }    print(ans);}