Submission #862197

#	Time	Username	Problem	Language	Result	Execution time	Memory
862197		Kubogi	Two Antennas (JOI19_antennas)	C++17	100 / 100	685 ms	65756 KiB

antennas

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

#define int long long
#define fileio(name) if (fopen(name".inp", "r")) freopen(name".inp", "r", stdin), freopen(name".out", "w", stdout)

const int maxn = 2e5+4, inf = 1e18;
int n, q, h[maxn], a[maxn], b[maxn], ans[maxn], l[maxn], r[maxn];
vector<int> add[maxn], del[maxn];
vector<pair<int, int>> Q[maxn];

struct node {
    int mx = -inf, mn = inf, diff = -inf*2;
} st[maxn*4];

void pushdown(int id) {
    int x = st[id].mx;
    st[id].mx = -inf;

    st[id*2].mx = max(st[id*2].mx, x);
    st[id*2].diff = max(st[id*2].diff, st[id*2].mx - st[id*2].mn);

    st[id*2+1].mx = max(st[id*2+1].mx, x);
    st[id*2+1].diff = max(st[id*2+1].diff, st[id*2+1].mx - st[id*2+1].mn);
}
void update_mx(int id, int l, int r, int a, int b, int v) {
    if (r < a || b < l) return;
    if (a <= l && r <= b) {
        st[id].mx = max(st[id].mx, v);
        st[id].diff = max(st[id].diff, st[id].mx - st[id].mn);
        return;
    }
    pushdown(id);

    int mid = (l+r)>>1;
    update_mx(id*2, l, mid, a, b, v);
    update_mx(id*2+1, mid+1, r, a, b, v);

    st[id].diff = max(st[id*2].diff, st[id*2+1].diff);
}
void update_mn(int id, int l, int r, int i, int v) {
    if (i < l || i > r) return;
    if (l == r) {
        st[id].mx = -inf;
        st[id].mn = v;
        // st[id].diff = st[id].mx - st[id].mn;
        return;
    }
    pushdown(id);

    int mid = (l+r)>>1;
    update_mn(id*2, l, mid, i, v);
    update_mn(id*2+1, mid+1, r, i, v);

    st[id].mn = min(st[id*2].mn, st[id*2+1].mn);
    st[id].diff = max(st[id*2].diff, st[id*2+1].diff);
}
int query(int id, int l, int r, int a, int b) {
    if (r < a || b < l) return -inf;
    if (a <= l && r <= b) return st[id].diff;
    pushdown(id);

    int mid = (l+r)>>1;
    return max(query(id*2, l, mid, a, b), query(id*2+1, mid+1, r, a, b));
}

void solve() {
    for (int i = 1; i <= n*4; i++) {
        st[i] = {-inf, inf, -inf*2};
    }
    for (int i = 1; i <= n; i++) {
        add[i].clear();
        del[i].clear();
    }

    for (int i = n; i > 0; i--) {
        for (int j: add[i]) {
            update_mn(1, 1, n, j, h[j]);
        }
        for (int j: del[i]) {
            update_mn(1, 1, n, j, inf);
        }
        if (i + a[i] <= n) {
            update_mx(1, 1, n, i + a[i], min(n, i + b[i]), h[i]);
        }
        for (auto z: Q[i]) {
            ans[z.second] = max(ans[z.second], query(1, 1, n, i, z.first));
        }
        if (i - a[i] > 0) add[i - a[i]].push_back(i);
        if (i - b[i] - 1 > 0) del[i - b[i] - 1].push_back(i);
    }
}

int32_t main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    fileio("");
    // freopen("debug.txt", "w", stderr);

    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> h[i] >> a[i] >> b[i];
    }
    cin >> q;
    for (int i = 1; i <= q; i++) {
        cin >> l[i] >> r[i];
        Q[l[i]].push_back({r[i], i});
        ans[i] = -inf;
    }

    solve();
    reverse(h+1, h+1+n);
    reverse(a+1, a+1+n);
    reverse(b+1, b+1+n);
    for (int i = 1; i <= n; i++) {
        Q[i].clear();
    }
    for (int i = 1; i <= q; i++) {
        Q[n - r[i] + 1].push_back({n - l[i] + 1, i});
    }
    solve();

    for (int i = 1; i <= q; i++) {
        cout << ((ans[i] >= 0) ? ans[i] : -1) << "\n";
    }

    return 0 ^ 0;
}

Compilation message (stderr)

antennas.cpp: In function 'int32_t main()':
antennas.cpp:5:57: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    5 | #define fileio(name) if (fopen(name".inp", "r")) freopen(name".inp", "r", stdin), freopen(name".out", "w", stdout)
      |                                                  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
antennas.cpp:97:5: note: in expansion of macro 'fileio'
   97 |     fileio("");
      |     ^~~~~~
antennas.cpp:5:90: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    5 | #define fileio(name) if (fopen(name".inp", "r")) freopen(name".inp", "r", stdin), freopen(name".out", "w", stdout)
      |                                                                                   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
antennas.cpp:97:5: note: in expansion of macro 'fileio'
   97 |     fileio("");
      |     ^~~~~~

• Subtask 1: 2 / 2
• Subtask 2: 11 / 11
• Subtask 3: 22 / 22
• Subtask 4: 65 / 65