Submission #543421

#	Time	Username	Problem	Language	Result	Execution time	Memory
543421		SmolBrain	Fuel Station (NOI20_fuelstation)	C++17	43 / 100	265 ms	52048 KiB

FuelStation

// Om Namah Shivaya
// GM in 125 days

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define endl '\n'
#define pb push_back
#define conts continue
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "YES" << endl
#define no cout << "NO" << endl
#define ff first
#define ss second
#define ceil2(x,y) ((x+y-1) / (y))
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#ifndef ONLINE_JUDGE
#define debug(x) cout << #x <<" = "; print(x); cout << endl
#else
#define debug(x)
#endif

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

bool iseven(ll n) {if ((n & 1) == 0) return true; return false;}

void print(ll t) {cout << t;}
void print(int t) {cout << t;}
void print(string t) {cout << t;}
void print(char t) {cout << t;}
void print(double t) {cout << t;}
void print(ld t) {cout << t;}

template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(pair <T, V> p) {cout << "{"; print(p.ff); cout << ","; print(p.ss); cout << "}";}
template <class T> void print(vector <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T> void print(set <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T> void print(multiset <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T, class V> void print(map <T, V> v) {cout << "[ "; for (auto i : v) {print(i); cout << " ";} cout << "]";}
template<typename T> void amin(T &a, T b) { a = min(a, b); }
template<typename T> void amax(T &a, T b) { a = max(a, b); }

void usaco(string filename) {
    freopen((filename + ".in").c_str(), "r", stdin);
    freopen((filename + ".out").c_str(), "w", stdout);
}

const int MOD = 1e9 + 7;
const int maxn = 1e5 + 5;
const int inf1 = 1e9 + 5;
const ll inf2 = ll(1e18) + 5;

template<typename T>
struct segtree {
    /*=======================================================*/

    struct data {
        ll sum, mnpref;
    };

    data neutral = {0, inf2};

    void merge(data &curr, data &left, data &right) {
        curr.sum = left.sum + right.sum;
        curr.mnpref = min(left.mnpref, left.sum + right.mnpref);
    }

    void create(int x, int lx, int rx, T v) {
        tr[x] = {v, v};
    }

    void modify(int x, int lx, int rx, T v) {
        tr[x] = {v, v};
    }

    /*=======================================================*/

    int siz = 1;
    vector<data> tr;

    segtree(int n) {
        init(n);
    }

    segtree() {

    };

    void init(int n) {
        while (siz < n) siz *= 2;
        tr.assign(2 * siz, neutral);
    }

    void build(vector<T> &a, int n, int x, int lx, int rx) {
        if (rx - lx == 1) {
            if (lx < n) {
                create(x, lx, rx, a[lx]);
            }

            return;
        }

        int mid = (lx + rx) / 2;

        build(a, n, 2 * x + 1, lx, mid);
        build(a, n, 2 * x + 2, mid, rx);

        merge(tr[x], tr[2 * x + 1], tr[2 * x + 2]);
    }

    void build(vector<T> &a, int n) {
        build(a, n, 0, 0, siz);
    }

    void pupd(int i, T v, int x, int lx, int rx) {
        if (rx - lx == 1) {
            modify(x, lx, rx, v);
            return;
        }

        int mid = (lx + rx) / 2;

        if (i < mid) {
            pupd(i, v, 2 * x + 1, lx, mid);
        }
        else {
            pupd(i, v, 2 * x + 2, mid, rx);
        }

        merge(tr[x], tr[2 * x + 1], tr[2 * x + 2]);
    }

    void pupd(int i, T v) {
        pupd(i, v, 0, 0, siz);
    }

    data query(int l, int r, int x, int lx, int rx) {
        if (lx >= r or rx <= l) return neutral;
        if (lx >= l and rx <= r) return tr[x];

        int mid = (lx + rx) / 2;

        data curr;
        data left = query(l, r, 2 * x + 1, lx, mid);
        data right = query(l, r, 2 * x + 2, mid, rx);

        merge(curr, left, right);
        return curr;
    }

    data query(int l, int r) {
        return query(l, r + 1, 0, 0, siz);
    }
};

void solve(int test_case)
{
    ll n, d; cin >> n >> d;
    vector<array<ll, 3>> a(n);
    rep(i, n) rep(j, 3) cin >> a[i][j];

    sort(all(a));

    vector<ll> diff(n + 5);
    diff[0] = a[0][0];
    rep1(i, n - 1) diff[i] = a[i][0] - a[i - 1][0];
    diff[n] = d - a[n - 1][0];

    auto check = [&](ll f) {
        ll prev = 0, fuel = f;

        rep(i, n) {
            auto [x, add, mx] = a[i];
            ll dis = x - prev;
            fuel -= dis;

            if (fuel < 0) {
                return false;
            }

            if (f <= mx) {
                fuel += add;
            }

            prev = x;
        }

        ll dis = d - prev;
        fuel -= dis;

        if (fuel < 0) return false;

        return true;
    };

    vector<ll> b(n);
    rep(i, n) b[i] = a[i][0];

    sort(all(b));
    auto it = unique(all(b));
    b.resize(it - b.begin());

    segtree<ll> st(2 * n + 5);
    rep(i, n + 1) st.pupd(2 * (i + 1), -diff[i]);

    ll ans = d;

    vector<array<ll, 3>> c(n);
    rep(i, n) {
        auto [x, toadd, mx] = a[i];
        x = lower_bound(all(b), x) - b.begin() + 1;
        c[i] = {mx, x, toadd};
    }

    sort(rall(c));

    ll l = -1, r = -1;

    rep(i, n) {
        auto [mx, x, toadd] = c[i];
        st.pupd(2 * x + 1, toadd);

        ll mnpref = st.query(0, 2 * n + 2).mnpref;
        ll first = 0;

        if (mnpref < 0) {
            first = abs(mnpref);
        }

        if (first <= mx) {
            amin(ans, first);
        }

        // if (mnpref >= 0) {
        //     if (i + 1 < n) {
        //         l = c[i + 1][0] + 1;
        //     }
        //     else {
        //         l = 1;
        //     }

        //     r = f;
        //     debug(l);
        //     debug(r);

        //     while (l <= r) {
        //         ll mid = (l + r) / 2;
        //         st.pupd(0, mid);

        //         mnpref = st.query(0, 2 * n + 2).mnpref;

        //         if (mnpref >= 0) {
        //             amin(ans, f);
        //             r = mid - 1;
        //         }
        //         else {
        //             l = mid + 1;
        //         }
        //     }

        //     st.pupd(0, 20);
        //     debug(st.query(0, 2 * n + 2).mnpref);
        // }
    }

    cout << ans << endl;

    // if (l == -1) {
    //     cout << ans << endl;
    //     return;
    // }

    // while (l <= r) {
    //     ll mid = (l + r) / 2;
    //     if (check(mid)) {
    //         amin(ans, mid);
    //         r = mid - 1;
    //     }
    //     else {
    //         l = mid + 1;
    //     }
    // }

    // cout << ans << endl;
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;
    rep1(i, t) {
        solve(i);
    }

    return 0;
}

Compilation message (stderr)

FuelStation.cpp: In function 'void solve(int)':
FuelStation.cpp:189:10: warning: variable 'check' set but not used [-Wunused-but-set-variable]
  189 |     auto check = [&](ll f) {
      |          ^~~~~
FuelStation.cpp:237:8: warning: unused variable 'l' [-Wunused-variable]
  237 |     ll l = -1, r = -1;
      |        ^
FuelStation.cpp:237:16: warning: unused variable 'r' [-Wunused-variable]
  237 |     ll l = -1, r = -1;
      |                ^
FuelStation.cpp: In function 'void usaco(std::string)':
FuelStation.cpp:64:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |     freopen((filename + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
FuelStation.cpp:65:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |     freopen((filename + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 0 / 13
• Subtask 3: 17 / 17
• Subtask 4: 0 / 12
• Subtask 5: 19 / 19
• Subtask 6: 0 / 11
• Subtask 7: 0 / 21