Submission #649578

#	Time	Username	Problem	Language	Result	Execution time	Memory
649578		KoalaMuch	Salesman (IOI09_salesman)	C++14	100 / 100	1922 ms	39952 KiB

salesman

#include<bits/stdc++.h>
using namespace std;
const int N = 5e5+4;
int sm[N*4][2];
vector<pair<int,int>> fair[N];
int old[N];
int can[N];
void build(int l,int r,int now,int u,int d){
    if(l==r){
        sm[now][0] = -2e9+l*d;
        sm[now][1] = -2e9-l*u;
        return ;
    }
    int mid = (l+r) >> 1;
    build(l,mid,now<<1,u,d),build(mid+1,r,now<<1|1,u,d);
    sm[now][0] = max(sm[now<<1][0],sm[now<<1|1][0]);
    sm[now][1] = max(sm[now<<1][1],sm[now<<1|1][1]);
}
void update(int l,int r,int id,int now,int v,int t,bool rep){
    if(l>id||r<id)  return ;
    if(l==r){
        if(!rep)    sm[now][t] = max(sm[now][t],v);
        else        sm[now][t] = v;
        return ;
    }
    int mid = (l+r) >> 1;
    update(l,mid,id,now<<1,v,t,rep),update(mid+1,r,id,now<<1|1,v,t,rep);
    sm[now][t] = max(sm[now<<1][t],sm[now<<1|1][t]);
}
int query(int l,int r,int ll,int rr,int now,int t){
    if(l>rr||r<ll)  return -INT_MAX;
    if(l>=ll&&r<=rr)    return sm[now][t];
    int mid = (l+r) >> 1;
    return max(query(l,mid,ll,rr,now<<1,t),query(mid+1,r,ll,rr,now<<1|1,t));
}
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n,u,d,s,day,loc,pro;
    cin >> n >> u >> d >> s;
    for(int i=0;i<n;i++){
        cin >> day >> loc >> pro;
        fair[day].push_back({loc,pro});
    }
    int ans = 0;
    build(1,500001,1,u,d);
    update(1,500001,s,1,s*d,0,false);
    update(1,500001,s,1,-s*u,1,false);
    for(int i=1;i<=500001;i++){
        sort(fair[i].begin(),fair[i].end());
        for(int j=0;j<fair[i].size();j++){
            loc = fair[i][j].first,pro = fair[i][j].second;
            old[loc] = query(1,500001,loc,loc,1,0)-loc*d;
            int fromd = query(1,500001,1,loc,1,0)+pro-loc*d,fromu = query(1,500001,loc,500001,1,1)+pro+loc*u;
            int bestV = max(fromu,fromd);
            can[loc] = bestV;
            //if(loc==80)  cout << fromd << " " << fromu << " " << query(1,500001,loc,500001,1,1) << "\n";
            update(1,500001,loc,1,bestV+d*loc,0,false);
            update(1,500001,loc,1,bestV-u*loc,1,false);
        }
        for(int j=0;j<fair[i].size();j++){
            loc = fair[i][j].first;
            update(1,500001,loc,1,old[loc]+d*loc,0,true);
            update(1,500001,loc,1,old[loc]-u*loc,1,true);
        }
        for(int j=fair[i].size()-1;j>=0;j--){
            loc = fair[i][j].first,pro=fair[i][j].second;
            int fromd = query(1,500001,1,loc,1,0)+pro-loc*d,fromu = query(1,500001,loc,500001,1,1)+pro+loc*u;
            int bestV = max(fromu,fromd);
            can[loc] = max(can[loc],bestV);
            update(1,500001,loc,1,bestV+d*loc,0,false);
            update(1,500001,loc,1,bestV-u*loc,1,false);
        }
        for(int j=0;j<fair[i].size();j++){
            loc = fair[i][j].first;
            update(1,500001,loc,1,can[loc]+d*loc,0,false);
            update(1,500001,loc,1,can[loc]-u*loc,1,false);
            if(loc<s)   ans = max(ans,can[loc]-d*(s-loc));
            else        ans = max(ans,can[loc]-u*(loc-s));
        }
        //if(fair[i].size())  cout << ans << "\n";
    }
    cout << ans << "\n";
    return 0;
}

Compilation message (stderr)

salesman.cpp: In function 'int main()':
salesman.cpp:51:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   51 |         for(int j=0;j<fair[i].size();j++){
      |                     ~^~~~~~~~~~~~~~~
salesman.cpp:61:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   61 |         for(int j=0;j<fair[i].size();j++){
      |                     ~^~~~~~~~~~~~~~~
salesman.cpp:74:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   74 |         for(int j=0;j<fair[i].size();j++){
      |                     ~^~~~~~~~~~~~~~~

• Subtask 1: 100 / 100