Submission #973216

#	Time	Username	Problem	Language	Result	Execution time	Memory
973216		wapas	Salesman (IOI09_salesman)	C++17	80 / 100	393 ms	33228 KiB

salesman

// code by wapas
#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

/*
  segtree code by : https://github.com/atcoder/ac-library/blob/master/atcoder/segtree.hpp
  how to use : https://github.com/atcoder/ac-library/blob/master/document_en/segtree.md
*/
#if __cplusplus < 202002L
unsigned int bit_ceil(unsigned int n) {
    unsigned int x = 1;
    while (x < (unsigned int)(n)) x *= 2;
    return x;
}
#endif

int countr_zero(unsigned int n) {
#ifdef _MSC_VER
    unsigned long index;
    _BitScanForward(&index, n);
    return index;
#else
    return __builtin_ctz(n);
#endif
}

template <class S, auto op, auto e> struct segtree {
    static_assert(is_convertible_v<decltype(op), function<S(S, S)>>,
                  "op must work as S(S, S)");
    static_assert(is_convertible_v<decltype(e), function<S()>>,
                  "e must work as S()");
  
  public:
    segtree() : segtree(0) {}
    explicit segtree(int n) : segtree(vector<S>(n, e())) {}
    explicit segtree(const vector<S>& v) : _n(int(v.size())) {
        size = (int) bit_ceil((unsigned int)(_n));
        log = countr_zero((unsigned int)size);
        d = vector<S>(2 * size, e());
        for (int i = 0; i < _n; i++) d[size + i] = v[i];
        for (int i = size - 1; i >= 1; i--) {
            update(i);
        }
    }

    void set(int p, S x) {
        assert(0 <= p && p < _n);
        p += size;
        d[p] = x;
        for (int i = 1; i <= log; i++) update(p >> i);
    }

    S get(int p) const {
        assert(0 <= p && p < _n);
        return d[p + size];
    }

    S prod(int l, int r) const {
        assert(0 <= l && l <= r && r <= _n);
        S sml = e(), smr = e();
        l += size;
        r += size;

        while (l < r) {
            if (l & 1) sml = op(sml, d[l++]);
            if (r & 1) smr = op(d[--r], smr);
            l >>= 1;
            r >>= 1;
        }
        return op(sml, smr);
    }

    S all_prod() const { return d[1]; }

    template <bool (*f)(S)> int max_right(int l) const {
        return max_right(l, [](S x) { return f(x); });
    }
    template <class F> int max_right(int l, F f) const {
        assert(0 <= l && l <= _n);
        assert(f(e()));
        if (l == _n) return _n;
        l += size;
        S sm = e();
        do {
            while (l % 2 == 0) l >>= 1;
            if (!f(op(sm, d[l]))) {
                while (l < size) {
                    l = (2 * l);
                    if (f(op(sm, d[l]))) {
                        sm = op(sm, d[l]);
                        l++;
                    }
                }
                return l - size;
            }
            sm = op(sm, d[l]);
            l++;
        } while ((l & -l) != l);
        return _n;
    }

    template <bool (*f)(S)> int min_left(int r) const {
        return min_left(r, [](S x) { return f(x); });
    }
    template <class F> int min_left(int r, F f) const {
        assert(0 <= r && r <= _n);
        assert(f(e()));
        if (r == 0) return 0;
        r += size;
        S sm = e();
        do {
            r--;
            while (r > 1 && (r % 2)) r >>= 1;
            if (!f(op(d[r], sm))) {
                while (r < size) {
                    r = (2 * r + 1);
                    if (f(op(d[r], sm))) {
                        sm = op(d[r], sm);
                        r--;
                    }
                }
                return r + 1 - size;
            }
            sm = op(d[r], sm);
        } while ((r & -r) != r);
        return 0;
    }

  private:
    int _n, size, log;
    vector<S> d;

    void update(int k) { d[k] = op(d[2 * k], d[2 * k + 1]); }
};

struct market {
    ll date, pos, profit;
    bool operator < (const market &o) const {
        if (date == o.date) return pos < o.pos;
        return date < o.date;
    } 
};

ll op(ll a, ll b) {
    return max(a, b);
}

const ll inf = -1e18;
ll e() {
    return inf;
}

#define SEG_MAX 505050
void solution(int t) {
    int N, U, D, S; cin >> N >> U >> D >> S;
    vector<market> arr;
    arr.push_back({ (int) 1e8, -1, 0 });
    for (int i = 0; i < N; i++) {
        ll d, p, c; cin >> d >> p >> c;
        arr.push_back({ d, p, c });
    }
    N += 1;
    sort(arr.begin(), arr.end());
    segtree<ll, op, e> stD(SEG_MAX), stU(SEG_MAX);
    auto setST = [&](int x, int v) {
        stD.set(x, v + x * D);
        stU.set(x, v - x * U);
    };
    auto getST = [&](int x) {
        return max(stD.prod(0, x) - x * D, stU.prod(x + 1, SEG_MAX) + x * U);
    };
    setST(S, 0);
    ll last = arr[0].date, lastIdx = 0;
    for (int i = 0; i < N; i++) {
        if (last == arr[i].date) continue;
        int M = i - lastIdx;
        vector<ll> cacheD(M, inf), cacheU(M, inf);
        for (int j = 0; j < M; j++) {
            int k = lastIdx + j;
            cacheD[j] = cacheU[j] = getST(arr[k].pos);
        }
        for (int j = 0; j < M; j++) {
            int k = lastIdx + j;
            if (j != 0) cacheD[j] = max(cacheD[j], cacheD[j - 1] - (arr[k].pos - arr[k - 1].pos) * D);
            cacheD[j] += arr[k].profit;
        }
        for (int j = M - 1; j >= 0; j--) {
            int k = lastIdx + j;
            if (j != M - 1) cacheU[j] = max(cacheU[j], cacheU[j + 1] - (arr[k + 1].pos - arr[k].pos) * U);
            cacheU[j] += arr[k].profit;
        }
        for (int j = 0; j < M; j++) {
            int k = lastIdx + j;
            setST(arr[k].pos, max(cacheD[j], cacheU[j]));
        }
        last = arr[i].date; lastIdx = i;
    }
    cout << getST(S);
}

int main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
    // int T; cin >> T;
    int T = 1;
    for (int t = 0; t < T; t++) {
        solution(t);
    }
}

• Subtask 1: 80 / 100