Codeforces 1207 G. Indie Album
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Codeforces 1207 G. Indie Album
解题思路
离线下来用SAM或者AC自动机就是一个单点加子树求和,套个树状数组就好了,因为这个题广义SAM不能存在 \(len[u] = len[fa]\) 的节点,需要特殊处理,所以写一个博客来贴板子,之前用Awd博客上的那个好像不太能处理干净。
code
/*program by mangoyang*/
#include <bits/stdc++.h>
#define inf ((ll) 1e18)
#define Max(a, b) ((a) > (b) ? (a) : (b))
#define Min(a, b) ((a) < (b) ? (a) : (b))
typedef long long ll;
using namespace std;
template <class T>
inline void read(T &x){
int ch = 0, f = 0; x = 0;
for(; !isdigit(ch); ch = getchar()) if(ch == '-') f = 1;
for(; isdigit(ch); ch = getchar()) x = x * 10 + ch - 48;
if(f) x = -x;
}
const int N = 1600005;
vector<int> g[N], d[N], rt;
vector<pair<int, int> > q[N];
string str[N];
char strr[N];
int ans[N], n, m;
namespace Bit{
int s[N];
inline void modify(int x, int y){
for(int i = x; i < N; i += i & -i) s[i] += y;
}
inline int query(int l, int r){
int res = 0;
for(int i = l - 1; i; i -= i & -i) res -= s[i];
for(int i = r; i; i -= i & -i) res += s[i];
return res;
}
}
namespace SAM{
vector<int> g[N];
int ch[N][26], dfn[N], len[N], fa[N], sz[N], size = 1, tail = 1, cnt;
inline int newnode(int x){ return len[++size] = x, size; }
inline void ins(int c, int pos){
int p = tail;
if(ch[p][c]){
if(ch[p][c] && len[ch[p][c]] == len[p] + 1){
int np = ch[p][c];
if(pos <= n) d[pos].push_back(np);
return (void) (tail = np);
}
int np = newnode(len[p] + 1), q = ch[p][c];
if(pos <= n) d[pos].push_back(np);
fa[np] = fa[q], fa[q] = np;
for(int i = 0; i < 26; i++) ch[np][i] = ch[q][i];
for(; p && ch[p][c] == q; p = fa[p]) ch[p][c] = np;
return (void) (tail = np);
}
int np = newnode(len[p] + 1);
if(pos <= n) d[pos].push_back(np);
for(; p && !ch[p][c]; p = fa[p]) ch[p][c] = np;
if(!p) return (void) (fa[np] = 1, tail = np);
int q = ch[p][c];
if(len[q] == len[p] + 1) fa[np] = q;
else{
int nq = newnode(len[p] + 1);
fa[nq] = fa[q], fa[q] = fa[np] = nq;
for(int i = 0; i < 26; i++) ch[nq][i] = ch[q][i];
for(; p && ch[p][c] == q; p = fa[p]) ch[p][c] = nq;
} tail = np;
}
inline void addedge(){
for(int i = 2; i <= size; i++) g[fa[i]].push_back(i);
}
inline void dfs(int u){
dfn[u] = ++cnt, sz[u] = 1;
for(int i = 0; i < (int) g[u].size(); i++)
dfs(g[u][i]), sz[u] += sz[g[u][i]];
}
}
inline void build(int u){
int tmp = SAM::tail;
for(int i = 0; i < (int) str[u].size(); i++)
SAM::ins(str[u][i] - 'a', u);
for(int i = 0; i < (int) g[u].size(); i++)
build(g[u][i]);
SAM::tail = tmp;
}
inline void solve(int u){
for(int i = 0; i < (int) d[u].size(); i++)
Bit::modify(SAM::dfn[d[u][i]], 1);
for(int i = 0; i < (int) q[u].size(); i++){
int x = q[u][i].first, y = q[u][i].second;
ans[x] = Bit::query(SAM::dfn[y], SAM::dfn[y] + SAM::sz[y] - 1);
}
for(int i = 0; i < (int) g[u].size(); i++)
solve(g[u][i]);
for(int i = 0; i < (int) d[u].size(); i++)
Bit::modify(SAM::dfn[d[u][i]], -1);
}
int main(){
read(n);
for(int i = 1, x, y; i <= n; i++){
read(x);
if(x == 1)
cin >> str[i], rt.push_back(i);
else
read(y), cin >> str[i], g[y].push_back(i);
}
for(int i = 0; i < (int) rt.size(); i++)
build(rt[i]);
read(m);
for(int i = 1, x; i <= m; i++){
read(x), scanf("%s", strr);
int lenth = strlen(strr);
for(int j = 0; j < lenth; j++)
SAM::ins(strr[j] - 'a', n + 1);
q[x].push_back(make_pair(i, SAM::tail));
SAM::tail = 1;
}
SAM::addedge(), SAM::dfs(1);
for(int i = 0; i < (int) rt.size(); i++)
solve(rt[i]);
for(int i = 1; i <= m; i++) printf("%d\n", ans[i]);
return 0;
}
标签:Album,rt,ch,Indie,res,1207,len,int,inline 来源: https://www.cnblogs.com/mangoyang/p/11455519.html