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답안 #146296

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
146296 2019-08-23T10:40:23 Z popovicirobert Salesman (IOI09_salesman) C++14
100 / 100
 496 ms 43672 KB 
#include <bits/stdc++.h>
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long


#if 0
const int MOD = ;

inline int lgput(int a, int b) {
    int ans = 1;
    while(b > 0) {
        if(b & 1) ans = (1LL * ans * a) % MOD;
        b >>= 1;
        a = (1LL * a * a) % MOD;
    }
    return ans;
}

inline void mod(int &x) {
    if(x >= MOD)
        x -= MOD;
}

inline void add(int &x, int y) {
    x += y;
    mod(x);
}

inline void sub(int &x, int y) {
    x += MOD - y;
    mod(x);
}

inline void mul(int &x, int y) {
    x = (1LL * x * y) % MOD;
}

inline int inv(int x) {
    return lgput(x, MOD - 2);
}
#endif

#if 0
int fact[], invfact[];

inline void prec(int n) {
    fact[0] = 1;
    for(int i = 1; i <= n; i++) {
        fact[i] = (1LL * fact[i - 1] * i) % MOD;
    }
    invfact[n] = lgput(fact[n], MOD - 2);
    for(int i = n - 1; i >= 0; i--) {
        invfact[i] = (1LL * invfact[i + 1] * (i + 1)) % MOD;
    }
}

inline int comb(int n, int k) {
    if(n < k) return 0;
    return (1LL * fact[n] * (1LL * invfact[k] * invfact[n - k] % MOD)) % MOD;
}
#endif

using namespace std;

const int INF = 2e9;
const int MAXN = (int) 5e5 + 5;

vector < pair <int, int> > offers[MAXN + 1];

struct Fenwick {
    vector <int> aib;
    int n;

    inline void init(int _n) {
        n = _n;
        aib.resize(n + 1, -INF);
    }

    inline void update(int pos, int val) {
        for(int i = pos; i <= n; i += lsb(i)) {
            aib[i] = max(aib[i], val);
        }
    }

    inline int query(int pos) {
        int ans = -INF;
        for(int i = pos; i > 0; i -= lsb(i)) {
            ans = max(ans, aib[i]);
        }
        return ans;
    }
};

int dp[MAXN + 1], aux[MAXN + 1];

int main() {
#if 0
    ifstream cin("A.in");
    ofstream cout("A.out");
#endif
    int i, n, u, d, s;
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    cin >> n >> u >> d >> s;
    for(i = 1; i <= n; i++) {
        int t, x, c;
        cin >> t >> x >> c;
        offers[t].push_back({x, c});
    }

    fill(dp, dp + MAXN + 1, -INF);
    dp[s] = 0;

    Fenwick fen1, fen2;
    fen1.init(MAXN), fen2.init(MAXN);
    fen1.update(MAXN - s, -u * s);
    fen2.update(s, d * s);

    for(int t = 1; t <= MAXN; t++) {
        sort(offers[t].begin(), offers[t].end());

        int sz = offers[t].size();
        for(i = 1; i < sz; i++) {
            offers[t][i].second += offers[t][i - 1].second;
        }
        for(auto it : offers[t]) {
            aux[it.first] = -INF;
        }
        for(auto it : offers[t]) {
            aux[it.first] = max(aux[it.first], max(-it.first * d + fen2.query(it.first), it.first * u + fen1.query(MAXN - it.first)));
        }

        int mx = -INF;
        for(i = sz - 1; i >= 0; i--) {
            int x = offers[t][i].first;
            mx = max(mx, aux[x] - u * x + offers[t][i].second);
            dp[x] = max(dp[x], mx - (i > 0 ? offers[t][i - 1].second : 0) + u * x);
        }
        mx = -INF;
        for(i = 0; i < sz; i++) {
            int x = offers[t][i].first;
            mx = max(mx, aux[x] + d * x - (i > 0 ? offers[t][i - 1].second : 0));
            dp[x] = max(dp[x], mx - d * x + offers[t][i].second);
        }

        for(auto it : offers[t]) {
            int x = it.first;
            fen1.update(MAXN - x, dp[x] - u * x);
            fen2.update(x, dp[x] + d * x);
        }
    }

    auto get = [&](int a, int b) {
        if(a <= b) return (b - a) * d;
        return (a - b) * u;
    };

    int ans = -INF;
    for(i = 1; i <= MAXN; i++) {
        ans = max(ans, dp[i] - get(i, s));
    }
    cout << ans;

    return 0;
}

/*
dp[t][x]
x1 <= x2

dp[t + 1][x2] = dp[t][x] + sp[t + 1][x2] - sp[t + 1][x1 - 1] - U * (x - x1) - D * (x2 - x1)
dp[t + 1][x1] = dp[t][x] + sp[t + 1][x2] - sp[t + 1][x1 - 1] - D * (x2 - x) - U * (x2 - x1)

(x1 <= x)
dp[t + 1][x2] =

sp[t + 1][x2] - D * x2
dp[t][x] - U * x
-sp[t + 1][x1 - 1] + x1 * (D + U)




(x2 >= x)
dp[t + 1][x1] =

sp[t + 1][x2] - x2 * (D + U)
dp[t][x] + D * x
-sp[t + 1][x1 - 1] + U * x1
*/

Subtask #1
100.0 / 100.0

# 결과 실행 시간 메모리 Grader output
1 Correct 21 ms 18044 KB Output is correct
2 Correct 20 ms 17912 KB Output is correct
3 Correct 20 ms 18040 KB Output is correct
4 Correct 21 ms 18040 KB Output is correct
5 Correct 23 ms 18168 KB Output is correct
6 Correct 41 ms 20856 KB Output is correct
7 Correct 72 ms 22468 KB Output is correct
8 Correct 122 ms 25016 KB Output is correct
9 Correct 159 ms 27000 KB Output is correct
10 Correct 272 ms 34100 KB Output is correct
11 Correct 318 ms 34684 KB Output is correct
12 Correct 389 ms 38520 KB Output is correct
13 Correct 411 ms 38776 KB Output is correct
14 Correct 488 ms 43596 KB Output is correct
15 Correct 449 ms 43640 KB Output is correct
16 Correct 496 ms 43672 KB Output is correct
17 Correct 21 ms 17912 KB Output is correct
18 Correct 20 ms 17912 KB Output is correct
19 Correct 21 ms 18040 KB Output is correct
20 Correct 21 ms 18168 KB Output is correct
21 Correct 21 ms 18040 KB Output is correct
22 Correct 25 ms 18168 KB Output is correct
23 Correct 23 ms 18040 KB Output is correct
24 Correct 23 ms 18296 KB Output is correct
25 Correct 73 ms 22264 KB Output is correct
26 Correct 128 ms 24772 KB Output is correct
27 Correct 201 ms 27844 KB Output is correct
28 Correct 234 ms 29036 KB Output is correct
29 Correct 287 ms 31352 KB Output is correct
30 Correct 291 ms 32396 KB Output is correct