Submission #1021952

#	Time	Username	Problem	Language	Result	Execution time	Memory
1021952		guagua0407	File Paths (BOI15_fil)	C++17	100 / 100	145 ms	52656 KiB

fil

//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int,int>
#define f first
#define s second
#define all(x) x.begin(),x.end()
#define _ ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

int dx[4]={0,0,1,-1};
int dy[4]={1,-1,0,0};

void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}

const int mxn=1e6+5;
vector<int> adj[mxn];
vector<ll> pre;
vector<int> p;
vector<int> l;
vector<int> ans;
int len;
int n,m,k;
vector<int> st;
vector<vector<int>> cand;
vector<int> cnt(mxn);

void dfs(int v){
    st.push_back(v);
    if(v<=n){
        for(auto u:st){
            cand[u].push_back(pre[v]+len-pre[u]);
        }
    }
    for(auto u:adj[v]){
        dfs(u);
    }
    st.pop_back();
}

void dfs2(int v){
    if(v<=n){
        for(auto x:cand[v]){
            if(x<mxn) cnt[x]++;
        }
    }
    else{
        int target=k-pre[v];
        if(target>0){
            for(int i=1;i*i<=target;i++){
                if(target%i==0){
                    if(cnt[i] or cnt[target/i]){
                        ans[v-n-1]=1;
                        break;
                    }
                }
            }
        }
    }
    for(auto u:adj[v]){
        dfs2(u);
    }
    if(v<=n){
        for(auto x:cand[v]){
            if(x<mxn) cnt[x]--;
        }
    }
}

int main() {_
    cin>>n>>m>>k;
    cin>>len;
    len++;
    pre.resize(n+m+1);
    p.resize(n+m+1);
    l.resize(n+m+1);
    for(int i=1;i<=n+m;i++){
        cin>>p[i]>>l[i];
        pre[i]=pre[p[i]]+l[i]+1;
    }
    for(int i=1;i<=n+m;i++){
        adj[p[i]].push_back(i);
    }
    ans.resize(m);
    cand.resize(n+1);
    dfs(0);
    dfs2(0);
    vector<ll> vec(n+1);
    for(int i=0;i<=n;i++){
        vec[i]=pre[i]+len;
    }
    vec.push_back(0);
    sort(all(vec));
    for(int i=0;i<m;i++){
        int pp=p[n+1+i],L=l[n+1+i];
        int cur=pre[pp]+L+1;
        bool tf=false;
        while(true){
            ll target=k-(cur-pre[pp]);
            int pos=lower_bound(all(vec),target)-vec.begin();
            if(pos!=n+1 and vec[pos]==target){
                tf=true;
            }
            if(tf or pp==0) break;
            pp=p[pp];
        }
        if(tf){
            ans[i]=1;
        }
    }
    for(int i=0;i<m;i++){
        cout<<(ans[i]?"YES":"NO")<<'\n';
    }
    return 0;
}
//maybe its multiset not set
//yeeorz
//laborz

Compilation message (stderr)

fil.cpp: In function 'void setIO(std::string)':
fil.cpp:15:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fil.cpp:16:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 33 / 33
• Subtask 2: 33 / 33
• Subtask 3: 34 / 34