Submission #375037

#	Time	Username	Problem	Language	Result	Execution time	Memory
375037		ijxjdjd	Salesman (IOI09_salesman)	C++14	80 / 100	1047 ms	59244 KiB

salesman

#include <bits/stdc++.h>
#define FR(i, N) for (int i = 0; i < int(N); i++)
#define all(x) begin(x), end(x)

using namespace std;

using ll = long long;

const int MAXN = (int)(5e5) + 5;
const int INF = (int)(1e9);
vector<pair<int, int>> byTime[MAXN];
int N, U, D, S;

int segDirect[2][4*MAXN];
int segBack[2][4*MAXN];
void pull(int n) {
    for (int j = 0; j < 2; j++) {
        segDirect[j][n] = max(segDirect[j][2*n], segDirect[j][2*n+1]);
        segBack[j][n] = max(segBack[j][2*n], segBack[j][2*n+1]);
    }
}
pair<int, int> query(int l, int r, bool right, int n = 1, int tl = 0, int tr = MAXN-1) {
    if (l > tr || r < tl) {
        return {-INF, -INF};
    }
    else if (l <= tl && tr <= r) {
        return {segDirect[right][n], segBack[right][n]};
    }
    else {
        int tm = (tl + tr)/2;
        auto p1 = query(l, r, right, 2*n, tl, tm);
        auto p2 = query(l, r, right, 2*n+1, tm+1, tr);
        return {max(p1.first, p2.first), max(p1.second, p2.second)};
    }
}
void upd(int i, int val, int n = 1, int tl = 0, int tr = MAXN-1) {
    if (tl == tr) {
            segBack[1][n] = val-U*i;
            segDirect[1][n] = val-U*i+i*(U+D);
            segBack[0][n] = val+D*i;
            segDirect[0][n] = val+D*i-i*(D+U);
    }
    else {
        int tm = (tl + tr)/2;
        if (i <= tm) {
            upd(i, val, 2*n, tl, tm);
        }
        else {
            upd(i, val, 2*n+1, tm+1, tr);
        }
        pull(n);
    }
}
int main() {
	cin.tie(0);
	cin.sync_with_stdio(0);
	cin >> N >> U >> D >> S;
	for (int i = 0; i < N; i++) {
        int T, L, K;
        cin >> T >> L >> K;
        byTime[T].push_back({L, K});
	}
	for (int i = 0; i < 4*MAXN; i++) {
        segBack[0][i] = -INF;
        segBack[1][i] = -INF;
        segDirect[0][i] = -INF;
        segDirect[1][i] = -INF;
	}
	int ans = -INF;
	upd(S, 0);
	for (auto& t : byTime) {
        sort(all(t));
        vector<int> res(t.size(), -INF);
        int curDirect = -INF;
        int curBack = -INF;
        int backKeep = -INF;
        int lst = MAXN;
        for (int i = int(t.size())-1; i>=0; i--) {
            auto qs = query(t[i].first, lst-1, false);

            curDirect = max(curDirect, qs.first) + t[i].second;
            curBack = max(curBack, backKeep + qs.second);

            res[i] = max(res[i], curDirect+U*t[i].first);
            res[i] = max(res[i], curBack+U*t[i].first+t[i].second);

            backKeep = max(backKeep, -t[i].first*(D+U));
            backKeep += t[i].second;
            curBack += t[i].second;

            lst = t[i].first;
        }

        curDirect = -INF;
        curBack = -INF;
        backKeep = -INF;
        lst = -1;
        for (int i = 0; i < t.size(); i++) {
            auto qs = query(lst+1, t[i].first, true);

            curDirect = max(curDirect, qs.first) + t[i].second;
            curBack = max(curBack, backKeep + qs.second);

            res[i] = max(res[i], curDirect - D*t[i].first);
            res[i] = max(res[i], curBack - D*t[i].first + t[i].second);


            backKeep = max(backKeep, t[i].first*(D+U));
            backKeep += t[i].second;
            curBack += t[i].second;

            lst = t[i].first;
        }
        for (int i = 0; i < t.size(); i++) {
            if (t[i].first < S) {
                ans = max(ans, res[i] - (S-t[i].first)*D);
            }
            else {
                ans = max(ans, res[i] - (t[i].first-S)*U);
            }
            upd(t[i].first, res[i]);
        }
	}
	cout << ans << '\n';
	return 0;
}

Compilation message (stderr)

salesman.cpp: In function 'int main()':
salesman.cpp:98:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   98 |         for (int i = 0; i < t.size(); i++) {
      |                         ~~^~~~~~~~~~
salesman.cpp:114:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  114 |         for (int i = 0; i < t.size(); i++) {
      |                         ~~^~~~~~~~~~

• Subtask 1: 80 / 100