Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 24393 Accepted Submission(s): 5862
题目链接:HDU 2896
题意显然就是用AC自动机了,把病毒网站的源码放在Trie图上跑一遍,如果遇到病毒id则把这个病毒放入这个网站的vector中即可且不需要回溯,但由于病毒可能之间存在子串的关系,因此要用一个数组来记录当前网站是否出现过这个病毒,不能重复出现。后台数据不强导致不记录也能AC,给一组数据:
2
aaa
aaaa
2
aaaaaa
bbaacc
答案:
web 1: 1 2
total: 1
代码:
#include <stdio.h>
#include <bits/stdc++.h>
using namespace std;
#define INF 0x3f3f3f3f
#define LC(x) (x<<1)
#define RC(x) ((x<<1)+1)
#define MID(x,y) ((x+y)>>1)
#define CLR(arr,val) memset(arr,val,sizeof(arr))
#define FAST_IO ios::sync_with_stdio(false);cin.tie(0);
typedef pair<int, int> pii;
typedef long long LL;
const double PI = acos(-1.0);
const int maxn = 510;
const int maxl = 210;
const int maxweb = 1010;
const int maxtar = 10010;
char key[maxl], tar[maxtar];
bitset<maxn>vis;
vector<int>web[maxweb];
struct Aho
{
struct Trie
{
int nxt[128];
int id, fail;
inline void reset()
{
id = 0;
fail = 0;
}
};
Trie L[maxn * maxl];
int sz;
void init()
{
sz = 1;
L[0].reset();
}
void insert(char s[], int id)
{
int u = 0, len = strlen(s);
for (int i = 0; i < len; ++i)
{
int v = s[i];
if (!L[u].nxt[v])
{
L[sz].reset();
L[u].nxt[v] = sz++;
}
u = L[u].nxt[v];
}
L[u].id = id;
}
void build()
{
L[0].fail = -1;
queue<int>Q;
Q.push(0);
while (!Q.empty())
{
int u = Q.front();
Q.pop();
for (int i = 0; i < 128; ++i)
{
int son = L[u].nxt[i];
if (!son)
continue;
Q.push(son);
if (!u)
L[son].fail = 0;
else
{
int f = L[u].fail;
while (~f)
{
if (L[f].nxt[i])
{
L[son].fail = L[f].nxt[i];
break;
}
f = L[f].fail;
}
if (f == -1)
L[son].fail = 0;
}
}
}
}
void match(char s[], int id)
{
int u = 0, len = strlen(s);
for (int i = 0; i < len; ++i)
{
int v = s[i];
if (L[u].nxt[v])
u = L[u].nxt[v];
else
{
int f = L[u].fail;
while (~f && !L[f].nxt[v])
f = L[f].fail;
if (f == -1)
u = 0;
else
u = L[f].nxt[v];
}
if (L[u].id && !vis[L[u].id])
{
web[id].push_back(L[u].id);
vis[L[u].id] = 1;
}
}
}
};
Aho aho;
void init()
{
for (int i = 0; i < maxweb; ++i)
web[i].clear();
aho.init();
}
int main(void)
{
int n, m, i, j;
while (~scanf("%d", &n))
{
init();
for (i = 1; i <= n; ++i)
{
scanf("%s", key);
aho.insert(key, i);
}
aho.build();
scanf("%d", &m);
for (i = 1; i <= m; ++i)
{
scanf("%s", tar);
vis.reset();
aho.match(tar, i);
}
int tot = 0;
for (i = 1; i <= m; ++i)
{
int sz = web[i].size();
if (!sz)
continue;
++tot;
sort(web[i].begin(), web[i].end());
printf("web %d: ", i);
for (j = 0; j < sz; ++j)
printf("%d%s", web[i][j], j == sz - 1 ? "\n" : " ");
}
printf("total: %d\n", tot);
}
return 0;
}
原文:http://www.cnblogs.com/Blackops/p/6424894.html