Submission #1169180

#	Time	Username	Problem	Language	Result	Execution time	Memory
1169180		vibeduck	Fuel Station (NOI20_fuelstation)	C++20	0 / 100	121 ms	27304 KiB

FuelStation

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

#define pb push_back
#define pf push_front
#define mp make_pair
#define fi first
#define se second
#define int long long
#define all(x) (x).begin(), (x).end()

typedef long double ld;
typedef long long ll;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<bool> vb;
typedef vector<vector<int>> vvi;
typedef vector<vector<bool>> vvb;
typedef vector<vector<ll>> vvll;
typedef vector<string> vs;
typedef vector<vector<string>> vvs;
typedef vector<char> vc;
typedef vector<vector<char>> vvc;
typedef map<int, int> mii;
typedef unordered_map<int, int> umii;

const int mod = 1e9 + 7;
const int inf = INTMAX_MAX;
const bool tc = false;

int n, d; int cnt;
const int N = 3e5 + 5;
const int defval = 1e18;
int seg[4 * N]; int lazy[4 * N];
int a[N];

void push(int l, int r, int pos) {
    seg[pos] += lazy[pos];
    if (l != r) {
        lazy[pos * 2] += lazy[pos];
        lazy[pos * 2 + 1] += lazy[pos];
    }
    lazy[pos] = 0;
}

int segfunction(int x, int y) {
    return min(x, y);
}

int query_util(int l, int r, int pos, int ql, int qr) {
    if (l > r) return defval;

    push(l, r, pos);

    if (ql > r || l > qr) {
        return defval;
    }
    if (ql <= l && r <= qr) {
        return seg[pos];
    }
    int mid = (l + r) / 2;
    return segfunction(query_util(l, mid, pos * 2, ql, qr), query_util(mid + 1, r, pos * 2 + 1, ql, qr));
}

void build_util(int l, int r, int pos) {
    if (l == r) {
        seg[pos] = a[l];
        return;
    }
    int mid = (l + r) / 2;
    build_util(l, mid, pos * 2);
    build_util(mid + 1, r, pos * 2 + 1);
    seg[pos] = segfunction(seg[pos * 2], seg[pos * 2 + 1]);
}

void update_util(int l, int r, int pos, int ql, int qr, int qval) {
    if (l > r) return;

    push(l, r, pos);

    if (qr < l || r < ql) return;

    if (ql <= l && r <= qr) {
        lazy[pos] += qval;
        push(l, r, pos);
        return;
    }

    int mid = (l + r) / 2;
    update_util(l, mid, pos * 2, ql, qr, qval);
    update_util(mid + 1, r, pos * 2 + 1, ql, qr, qval);
    seg[pos] = segfunction(seg[pos * 2], seg[pos * 2 + 1]);
}

void build() {
    build_util(0, cnt - 1, 1);
}

void update(int l, int r, int v) {
    update_util(0, cnt - 1, 1, l, r, v);
}

int query(int l, int r) {
    return query_util(0, cnt - 1, 1, l, r);
}

struct st {
    int x, a, b;
    bool operator<(st other) {
        return b > other.b;
    }
};

map<int, vector<st>> fuels;

inline void solve() {
    cin >> n >> d; swap(n, d);
    int ndn = 1; int nd0 = 1; vector<st> fv;
    for (int i = 0; i < d; i++) {
        int x, a, b;
        cin >> x >> a >> b;
        st s; s.x = x; s.a = a; s.b = b;
        fuels[x].pb(s); fv.pb(s);
        if (s.x == n) ndn = 0;
        if (s.x == 0) nd0 = 0;
    }

    if (nd0) {
        st s; s.x = 0;
        s.a = 0;
        s.b = 0;
        fuels[s.x].pb(s);
        fv.pb(s);
        //cnt++;
    }

    if (ndn) {
        st s; s.x = n;
        s.a = 0;
        s.b = 0;
        fuels[s.x].pb(s);
        fv.pb(s);
    }

    mii id; // id for each x
    sort(all(fv));


    vector<vector<st>> sv;
    for (auto it = fuels.begin(); it != fuels.end(); it++) {
        int x = it->first;
        vector<st> s = it->second;
        sv.pb(s);
        id[s[0].x] = cnt;
        cnt++;
        //cout << "buruuu\n";
    }

    for (int i = 1; i < sv.size(); i++) {
        a[i] = a[i - 1] - (sv[i][0].x - sv[i - 1][0].x);
    }

    build();

    // n -> distance, d -> number of fuel stations

    int ans = n;
    for (int i = fv.size() - 1; i >= 0; i--) {
        st f = fv[i];
        update(0, cnt - 1, f.b);

        //cout << "consider " << f.b << '\n';

        int x = f.x; int j = id[x];
        update(j + 1, cnt - 1, f.a);
        //cout << j + 1 << " -> " << cnt - 1 << '\n';
        int mn = query(0, cnt - 1);
        //cout << "minimum was " << mn << '\n';
        update(0, cnt - 1, -f.b);
        if (mn < 0) continue;
        int cand = f.b;
        int spr = mn;
        if (cand > spr) {
            assert(false);
            cand -= spr;
        } else {
            ans = 0;
            break;
        }

        ans = min(ans, cand);
    }
    cout << ans << '\n';
}

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

signed main() {
    ios::sync_with_stdio(false);
    cout.tie(0);
    cin.tie(0);
    //setIO();

    int t = 1;
    if (tc) {
        cin >> t;
    }

    while (t--) {
        solve();
    }
}

Compilation message (stderr)

FuelStation.cpp: In function 'void setIO(std::string)':
FuelStation.cpp:199:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  199 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
FuelStation.cpp:200:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  200 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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