Submission #337023

#	Time	Username	Problem	Language	Result	Execution time	Memory
337023		VROOM_VARUN	Salesman (IOI09_salesman)	C++14	100 / 100	1731 ms	65536 KiB

salesman

/*
ID: varunra2
LANG: C++
TASK: salesman
*/

#include <bits/stdc++.h>
using namespace std;

#ifdef DEBUG
#include "lib/debug.h"
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define debug_arr(...) \
  cerr << "[" << #__VA_ARGS__ << "]:", debug_arr(__VA_ARGS__)
#pragma GCC diagnostic ignored "-Wsign-compare"
//#pragma GCC diagnostic ignored "-Wunused-parameter"
//#pragma GCC diagnostic ignored "-Wunused-variable"
#else
#define debug(...) 42
#endif

#define EPS 1e-9
#define IN(A, B, C) assert(B <= A && A <= C)
#define INF (int)1e9
#define MEM(a, b) memset(a, (b), sizeof(a))
#define MOD 1000000007
#define MP make_pair
#define PB push_back
#define all(cont) cont.begin(), cont.end()
#define rall(cont) cont.end(), cont.begin()
#define x first
#define y second

const double PI = acos(-1.0);
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef map<int, int> MPII;
typedef multiset<int> MSETI;
typedef set<int> SETI;
typedef set<string> SETS;
typedef vector<int> VI;
typedef vector<PII> VII;
typedef vector<VI> VVI;
typedef vector<string> VS;

#define rep(i, a, b) for (int i = a; i < (b); ++i)
#define trav(a, x) for (auto& a : x)
#define sz(x) (int)(x).size()
typedef pair<int, int> pii;
typedef vector<int> vi;
#pragma GCC diagnostic ignored "-Wsign-compare"
// util functions

int n, u, d, s;

VVI fairs;

void init() { fairs.resize(n); }

const int mx = 500005;

struct segtree {
  VI st;
  VI lzy;
  int n;

  void init(int _n = 0) {
    _n = mx;
    n = _n;
    st.assign(4 * n, -INF);
    lzy.assign(4 * n, -INF);
  }

  void push(int node, int l, int r) {
    st[node] = max(st[node], lzy[node]);
    if (l < r) {
      lzy[2 * node + 1] = max(lzy[2 * node + 1], lzy[node]);
      lzy[2 * node + 2] = max(lzy[2 * node + 2], lzy[node]);
    }
    lzy[node] = -INF;
  }

  int qry(int ind, int node, int l, int r) {
    if (ind < l or ind > r) return -INF;
    push(node, l, r);
    if (ind == l and ind == r) return st[node];
    int mid = (l + r) / 2;
    return max(qry(ind, 2 * node + 1, l, mid),
               qry(ind, 2 * node + 2, mid + 1, r));
  }

  void upd(int tl, int tr, int val, int node, int l, int r) {
    if (tl > r or tr < l) return;
    push(node, l, r);
    if (l >= tl and r <= tr) {
      lzy[node] = max(lzy[node], val);
      push(node, l, r);
      return;
    }
    int mid = (l + r) / 2;
    upd(tl, tr, val, 2 * node + 1, l, mid);
    upd(tl, tr, val, 2 * node + 2, mid + 1, r);
    st[node] = max(st[2 * node + 1], st[2 * node + 2]);
  }

  int qry(int ind) { return qry(ind, 0, 0, n - 1); }

  void upd(int l, int r, int val) {
    if (l == -1) l = 0;
    if (r == -1) r = n - 1;
    r = min(r, n - 1);
    l = min(l, n - 1);
    upd(l, r, val, 0, 0, n - 1);
  }
} lft, rt;

int main() {
  // #ifndef ONLINE_JUDGE
  // freopen("salesman.in", "r", stdin);
  // freopen("salesman.out", "w", stdout);
  // #endif
  cin.sync_with_stdio(0);
  cin.tie(0);

  cin >> n >> u >> d >> s;

  init();
  lft.init();
  rt.init();

  for (int i = 0; i < n; i++) {
    fairs[i].resize(3);
    for (int j = 0; j < 3; j++) cin >> fairs[i][j];
  }

  sort(all(fairs));

  lft.upd(s, -1, s * d);
  rt.upd(-1, s, -s * u);

  // debug(lft.qry(0), s * d);

  VI dp(n, -INF);
  VI ndp(n, -INF);

  for (int i = 0, j = 0; i < n; i = j) {
    while (j < n and fairs[i][0] == fairs[j][0]) j++;
    int mx = -INF;
    int cop = i;
    for (int i = cop; i < j; i++) {
      int day, money, pos;
      day = fairs[i][0];
      pos = fairs[i][1];
      money = fairs[i][2];
      // debug("new uwa");
      // debug(lft.qry(pos), pos, d);
      // debug(lft.qry(pos) - pos * d);
      // debug(rt.qry(pos), pos, u);
      // debug(pos * u + rt.qry(pos));
      ndp[i] = max(lft.qry(pos) - pos * d, pos * u + rt.qry(pos)) + money;
      dp[i] = max(ndp[i], mx + money - pos * d);
      mx = max(mx + money, ndp[i] + pos * d);
    }
    mx = -INF;
    for (int i = j - 1; i >= cop; i--) {
      int day, money, pos;
      day = fairs[i][0];
      pos = fairs[i][1];
      money = fairs[i][2];
      dp[i] = max(dp[i], mx + money + pos * u);
      mx = max(mx + money, ndp[i] - pos * u);
      lft.upd(pos, -1, dp[i] + pos * d);
      rt.upd(-1, pos, dp[i] - pos * u);
    }
  }

  int ret = 0;

  // debug(dp);
  // debug(ndp);

  for (int i = 0; i < n; i++) {
    ret = max(ret, dp[i] - abs(fairs[i][1] - s) * (fairs[i][1] < s ? d : u));
  }

  cout << ret << '\n';

  return 0;
}

Compilation message (stderr)

salesman.cpp: In function 'int main()':
salesman.cpp:152:11: warning: variable 'day' set but not used [-Wunused-but-set-variable]
  152 |       int day, money, pos;
      |           ^~~
salesman.cpp:167:11: warning: variable 'day' set but not used [-Wunused-but-set-variable]
  167 |       int day, money, pos;
      |           ^~~

• Subtask 1: 100 / 100