Submission #862012

#	Time	Username	Problem	Language	Result	Execution time	Memory
862012		12345678	Salesman (IOI09_salesman)	C++17	100 / 100	618 ms	48084 KiB

salesman

#include <bits/stdc++.h>

using namespace std;

const int nx=5e5+5;
int n, u, d, s, x, y, z;
vector<pair<int, int>> t[nx];

struct segtree
{
    int d[4*nx];
    void build(int l, int r, int i)
    {
        if (l==r) return void(d[i]=-2e9);
        int md=(l+r)/2;
        build(l, md, 2*i);
        build(md+1, r, 2*i+1);
        d[i]=max(d[2*i], d[2*i+1]);
    }
    void update(int l, int r, int i, int idx, int vl)
    {
        if (idx<l||r<idx) return;
        if (l==r) return void(d[i]=max(d[i], vl));
        int md=(l+r)/2;
        update(l, md, 2*i, idx, vl);
        update(md+1, r, 2*i+1, idx, vl);
        d[i]=max(d[2*i], d[2*i+1]);
    }
    int query(int l, int r, int i, int ql, int qr)
    {
        if (r<ql||qr<l) return INT_MIN;
        if (ql<=l&&r<=qr) return d[i];
        int md=(l+r)/2;
        return max(query(l, md, 2*i, ql, qr), query(md+1, r, 2*i+1, ql, qr));
    }
} up, dn;

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n>>u>>d>>s;
    for (int i=0; i<n; i++) cin>>x>>y>>z, t[x].push_back({y, z});
    up.build(1, nx-1, 1); dn.build(1, nx-1, 1);
    up.update(1, nx-1, 1, s, -s*u); dn.update(1, nx-1, 1, s, s*d);
    for (int i=1; i<nx; i++)
    {
        sort(t[i].begin(), t[i].end());
        vector<int> cal(t[i].size()), tmp(t[i].size()), rtmp(t[i].size());
        for (int j=0; j<t[i].size(); j++)
        {
            int y=t[i][j].first, z=t[i][j].second;
            int qup=up.query(1, nx-1, 1, y, nx-1);
            int qdn=dn.query(1, nx-1, 1, 1, y);
            cal[j]=tmp[j]=rtmp[j]=max(qup+y*u, qdn-y*d)+z;
        }
        for (int j=1; j<t[i].size(); j++) tmp[j]=max(tmp[j], tmp[j-1]+(t[i][j].first-t[i][j-1].first)*(-d)+t[i][j].second);
        for (int j=(int)t[i].size()-2; j>=0; j--) rtmp[j]=max(rtmp[j], rtmp[j+1]+(t[i][j+1].first-t[i][j].first)*(-u)+t[i][j].second);
        for (int j=0; j<t[i].size(); j++) 
        {
            int y=t[i][j].first;
            //cout<<j<<' '<<tmp[j]<<' '<<rtmp[j]<<'\n';
            up.update(1, nx-1, 1, y, max(tmp[j], rtmp[j])-y*u);
            dn.update(1, nx-1, 1, y, max(tmp[j], rtmp[j])+y*d);
        }
    }
    cout<<max(up.query(1, nx-1, 1, s, nx-1)+s*u, dn.query(1, nx-1, 1, 1, s)-s*d);
}

Compilation message (stderr)

salesman.cpp: In function 'int main()':
salesman.cpp:49:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |         for (int j=0; j<t[i].size(); j++)
      |                       ~^~~~~~~~~~~~
salesman.cpp:56:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |         for (int j=1; j<t[i].size(); j++) tmp[j]=max(tmp[j], tmp[j-1]+(t[i][j].first-t[i][j-1].first)*(-d)+t[i][j].second);
      |                       ~^~~~~~~~~~~~
salesman.cpp:58:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |         for (int j=0; j<t[i].size(); j++)
      |                       ~^~~~~~~~~~~~

• Subtask 1: 100 / 100