Acwing 1285 单词

题意:
给出n个单词，文章由n个单词组成，求每个单词在文章中的出现次数

思路:

实现:

#include <stdio.h>
#include <string.h>
const int N = 1e6 + 5;
int tr[N][26], idx = 1, nex[N], q[N], id[N], f[N];
char s[N];

void insert(int x)
{
    int p = 0;
    int len = strlen(s + 1);
    for (int i = 1; i <= len; i++)
    {
        int t = s[i] - 'a';
        if (!tr[p][t])
            tr[p][t] = idx++;
        p = tr[p][t];
        f[p]++;
    }
    id[x] = p;
}

void build()
{
    int hh = 1, tt = 0;
    for (int i = 0; i < 26; i++)
        if (tr[0][i])
            q[++tt] = tr[0][i];

    while (hh <= tt)
    {
        int t = q[hh++];
        for (int i = 0; i < 26; i++)
        {
            int &p = tr[t][i];
            if (!p)
                p = tr[nex[t]][i];
            else
            {
                nex[p] = tr[nex[t]][i];
                q[++tt] = p;
            }
        }
    }
}

int main()
{
    int n;
    scanf("%d", &n);
    for (int i = 1; i <= n; i++)
    {
        scanf("%s", s + 1);
        insert(i);
    }
    build();
    for (int i = idx - 1; i >= 1; i--)
        f[nex[q[i]]] += f[q[i]];

    for (int i = 1; i <= n; i++)
        printf("%d\n", f[id[i]]);
    return 0;
}