Submission #1026727

#	Time	Username	Problem	Language	Result	Execution time	Memory
1026727		doducanh	Matching (CEOI11_mat)	C++14	100 / 100	168 ms	51968 KiB

mat

#include <bits/stdc++.h>

using namespace std;
#define ii pair<int,int>
#define fi first
#define se second
const int maxn=1e6+7;
int p[maxn];
int a[maxn];
ii pre[maxn];int h[maxn];
ii nex[maxn];int g[maxn];
int kmp[maxn];
int n,m;
void init(){
    vector<int>pos(n+2,0);
    for(int i=1;i<=n;i++)pos[p[i]]=i;
    for(int i=1;i<=n;i++)swap(pos[i],p[i]);
    for(int i=1;i<=n;i++){
        nex[i]={i+1,pos[i+1]};
        pre[i]={i-1,pos[i-1]};
    }
    for(int i=n;i>=1;i--){
        int k=p[i];
        h[i]=pre[k].se;
        g[i]=nex[k].se;
        pre[nex[k].fi]=pre[k];
        nex[pre[k].fi]=nex[k];
    }
}
bool can(int i,int j,int u,int v,bool type){
    if(i>n)return 0;
    if(type==0){
        if(u&&p[j-i+u]>p[j])return 0;
        if(v&&p[j-i+v]<p[j])return 0;
    }
    else{
        if(u&&a[j-i+u]>a[j])return 0;
        if(v&&a[j-i+v]<a[j])return 0;
    }
    return 1;
}
main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    cin>>n>>m;
    for(int i=1;i<=n;i++)cin>>p[i];
    init();
    for(int i=1;i<=m;i++)cin>>a[i];
//    for(int i=1;i<=n;i++){
//        cout<<h[i]<<" "<<g[i]<<"\n";
//    }
    kmp[1]=0;
    for(int i=2,j=0;i<=n;i++){
        while(j&&!can(j+1,i,h[j+1],g[j+1],0))j=kmp[j];
        if(can(j+1,i,h[j+1],g[j+1],0))j++;
        kmp[i]=j;
    }
//    for(int i=1;i<=n;i++)cout<<kmp[i]<<"\n";
//    cout<<8<<" "<<can(2,7,h[2],g[2],1)<<"\n";
    vector<int>ans;
    for(int i=1,j=0;i<=m;i++){
        while(j&&!can(j+1,i,h[j+1],g[j+1],1)){
            j=kmp[j];
        }
//        if(i==7)cout<<j<<"\n";
        if(can(j+1,i,h[j+1],g[j+1],1))j++;
//        if(i==7)cout<<j<<"\n";
        if(j==n)ans.push_back(i-n+1);
    }
    cout<<ans.size()<<"\n";
    for(int x:ans)cout<<x<<" ";
    return 0;
}

Compilation message (stderr)

mat.cpp:42:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   42 | main()
      | ^~~~

• Subtask 1: 9 / 9
• Subtask 2: 9 / 9
• Subtask 3: 9 / 9
• Subtask 4: 9 / 9
• Subtask 5: 9 / 9
• Subtask 6: 9 / 9
• Subtask 7: 9 / 9
• Subtask 8: 9 / 9
• Subtask 9: 8 / 8
• Subtask 10: 10 / 10
• Subtask 11: 10 / 10