[BZOJ]4567: [Scoi2016]背单词

#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdio>
#include <vector>
#include <stack>
#include <queue>
#include <cmath>
#include <set>
#include <map>
#define mp make_pair
#define pb push_back
#define pii pair<int,int>
#define link(x) for(edge *j=h[x];j;j=j->next)
#define inc(i,l,r) for(int i=l;i<=r;i++)
#define dec(i,r,l) for(int i=r;i>=l;i--)
const int MAXN=6e5+10;
const double eps=1e-8;
#define ll long long
using namespace std;
struct edge{int t,v;edge*next;}e[MAXN<<1],*h[MAXN],*o=e;
void add(int x,int y,int vul){o->t=y;o->v=vul;o->next=h[x];h[x]=o++;}
ll read(){
    ll x=0,f=1;char ch=getchar();
    while(!isdigit(ch)){if(ch==‘-‘)f=-1;ch=getchar();}
    while(isdigit(ch))x=x*10+ch-‘0‘,ch=getchar();
    return x*f;
}




typedef struct node{
    int ch[26],sum;bool flag;
}node;
node d[MAXN];
int cnt,rt,n;

void newnode(int &x){
    x=++cnt;d[x].sum=0;d[x].flag=0;
    inc(i,0,25)d[x].ch[i]=0;
}

ll ans;

void insert(string str){
    int temp=rt;int len=str.length();
    for(int i=0;i<len;i++){
	int t=str[i]-‘a‘;
	if(!d[temp].ch[t])newnode(d[temp].ch[t]);
	temp=d[temp].ch[t];
    }
    d[temp].flag=1;d[temp].sum++;
}

bool cmp(int aa,int bb){return d[aa].sum<d[bb].sum;}

vector<int>vec[MAXN];

void dfs(int x,int y){
    if(d[x].flag)vec[y].pb(x),y=x;
    for(int i=0;i<26;i++){
	if(d[x].ch[i])dfs(d[x].ch[i],y),d[x].sum+=d[d[x].ch[i]].sum;
    }
}

int p[MAXN],tot=0;

void slove(int x,int fa){
    p[x]=tot++,ans+=(p[x]-p[fa]);
    for(int i=0;i<vec[x].size();i++)slove(vec[x][i],x);
}

string s[MAXN];

int main(){
    ios::sync_with_stdio(false);
    cin>>n;
    inc(i,1,n)cin>>s[i],reverse(s[i].begin(),s[i].end());
    ans=0;
    newnode(rt);
    inc(i,1,n)insert(s[i]);
    dfs(rt,1);
    inc(i,1,cnt)sort(vec[i].begin(),vec[i].end(),cmp);
    slove(1,0);
    cout<<ans<<"\n";
}