Submission #921750

#	Time	Username	Problem	Language	Result	Execution time	Memory
921750		guagua0407	Road Construction (JOI21_road_construction)	C++17	100 / 100	8508 ms	61172 KiB

road_construction

//#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=250005;
const ll inf=2e9+5;
int n,k;
vector<pair<int,int>> vec;
vector<int> xs,ys;
vector<vector<int>> sir,sir2;
int bit[mxn];

void update(int pos,int val){
    pos++;
    for(;pos<mxn;pos+=(pos&-pos)){
        bit[pos]+=val;
    }
}

int query(int pos){
    pos++;
    int ans=0;
    for(;pos>0;pos-=(pos&-pos)){
        ans+=bit[pos];
    }
    return ans;
}

bool ok(ll d){
    vector<vector<pair<int,int>>> st(xs.size());
    vector<vector<pair<int,pair<int,int>>>> en(xs.size());
    for(int i=0;i<n;i++){
        int l=lower_bound(all(xs),max(-inf,(ll)xs[vec[i].f]-d))-xs.begin();
        int r=upper_bound(all(xs),min(inf,(ll)xs[vec[i].f]+d))-xs.begin()-1;
        int l2=lower_bound(all(ys),max(-inf,(ll)ys[vec[i].s]-d))-ys.begin();
        int r2=upper_bound(all(ys),min(inf,(ll)ys[vec[i].s]+d))-ys.begin()-1;
        if(l>0){
            st[l-1].push_back({l2,r2});
        }
        en[vec[i].f].push_back({vec[i].s,{l2,r2}});
    }
    memset(bit,0,sizeof(bit));
    ll ans=0;
    for(int i=0;i<(int)xs.size();i++){
        for(auto v:en[i]){
            ans+=(query(v.s.s)-query(v.s.f-1));
            update(v.f,1);
        }
        for(auto v:st[i]){
            ans-=(query(v.s)-query(v.f-1));
        }
        if(ans>=k) return true;
    }
    //cout<<d<<' '<<ans<<'\n';
    return ans>=k;
}

signed main() {_
    cin>>n>>k;
    vec.resize(n);
    for(int i=0;i<n;i++){
        int x,y;
        cin>>x>>y;
        int xx=y+x;
        int yy=y-x;
        vec[i]={xx,yy};
        xs.push_back(xx);
        ys.push_back(yy);
    }
    sort(all(xs));
    sort(all(ys));
    xs.resize(unique(all(xs))-xs.begin());
    ys.resize(unique(all(ys))-ys.begin());
    sir.resize(xs.size());
    sir2.resize(xs.size());
    for(int i=0;i<n;i++){
        //cout<<vec[i].f<<' '<<vec[i].s<<'\n';
        vec[i].f=lower_bound(all(xs),vec[i].f)-xs.begin();
        vec[i].s=lower_bound(all(ys),vec[i].s)-ys.begin();
        sir[vec[i].f].push_back(vec[i].s);
        sir2[vec[i].f].push_back(i);
    }
    ll l=0,r=(ll)4e9;
    while(l<r){
        ll mid=(l+r)/2;
        if(ok(mid)){
            r=mid;
        }
        else{
            l=mid+1;
        }
    }
    //cout<<l<<'\n';
    //return 0;
    ll d=l-1;
    vector<vector<pair<int,pair<int,int>>>> en(xs.size());
    for(int i=0;i<n;i++){
        int l2=lower_bound(all(ys),max(-inf,(ll)ys[vec[i].s]-d))-ys.begin();
        int r2=upper_bound(all(ys),min(inf,(ll)ys[vec[i].s]+d))-ys.begin()-1;
        en[vec[i].f].push_back({i,{l2,r2}});
    }
    set<pair<int,int>> S;
    deque<int> dq;
    vector<ll> ans;
    for(int i=0;i<(int)xs.size();i++){
        //cout<<xs[i]<<'\n';
        while(!dq.empty() and xs[vec[dq[0]].f]<max(-inf,(ll)xs[i]-d)){
            //cout<<"xxx "<<dq[0]<<' ';
            S.erase({vec[dq[0]].s,dq[0]});
            dq.pop_front();
        }
        for(auto v:en[i]){
            auto r=S.upper_bound({v.s.s,inf});
            for(auto it=S.lower_bound({v.s.f,-inf});it!=r;it++){
                int x=(*it).s;
                //cout<<x<<' '<<v.f<<'\n';
                ans.push_back(max(abs((ll)ys[vec[x].s]-(ll)ys[vec[v.f].s]),abs((ll)xs[vec[x].f]-(ll)xs[vec[v.f].f])));
            }
            S.insert({vec[v.f].s,v.f});
            dq.push_back(v.f);
        }
        //cout<<'\n';
    }
    sort(all(ans));
    while((int)ans.size()<k){
        ans.push_back(l);
    }
    for(auto v:ans){
        cout<<v<<'\n';
    }
    return 0;
}
//maybe its multiset not set
//yeeorz
//laborz

Compilation message (stderr)

road_construction.cpp: In function 'bool ok(long long int)':
road_construction.cpp:48:13: warning: unused variable 'r' [-Wunused-variable]
   48 |         int r=upper_bound(all(xs),min(inf,(ll)xs[vec[i].f]+d))-xs.begin()-1;
      |             ^
road_construction.cpp: In function 'void setIO(std::string)':
road_construction.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);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
road_construction.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: 5 / 5
• Subtask 2: 6 / 6
• Subtask 3: 7 / 7
• Subtask 4: 20 / 20
• Subtask 5: 27 / 27
• Subtask 6: 35 / 35