Submission #1297835

#TimeUsernameProblemLanguageResultExecution timeMemory
1297835khoile08Two Antennas (JOI19_antennas)C++20
100 / 100
308 ms42232 KiB
#include <bits/stdc++.h>
using namespace std;

#define FOR(i, a, b) for(int i = a; i <= b; i++)
#define FOD(i, a, b) for(int i = a; i >= b; i--)
//#define int long long
#define fi first
#define se second
#define ll long long
#define db double 
#define pb push_back
#define ii pair<int,int>
#define sq(i) (1LL * (i) * (i))
#define MASK(i) (1LL << i)
#define task "task"
#define close khoile1
#define open khoile2

const int inf = 1e9 + 4;
const ll INF = 1e18;
const int N = 2e5 + 4;

int n, q;
vector<ii> qu[N];
int a[N], b[N], h[N], ans[N];
vector<int> open[N], close[N];

struct Smt {
    int mxl[4 * N], mxr[4 * N], mnl[4 * N], mnr[4 * N], res[4 * N];

    void init() {
        FOR(i, 1, 4 * n) {
            mxl[i] = mxr[i] = res[i] = -inf;
            mnl[i] = mnr[i] = inf;
        }
    }

    void apply(int id, ii d) { /// max, min
        if(d.fi != -inf) {
            if(mnl[id] != inf) res[id] = max(res[id], abs(d.fi - mnl[id]));
            mxr[id] = max(mxr[id], d.fi);
        }
        if(d.se != inf) {
            if(mxl[id] != -inf) res[id] = max(res[id], abs(d.se - mxl[id]));
            mnr[id] = min(mnr[id], d.se);
        }
    }

    void pushdown(int id, int l, int r) {
        if(l == r) return;

        apply(id << 1, {mxr[id], mnr[id]});
        apply(id << 1 | 1, {mxr[id], mnr[id]});

        mxr[id] = -inf;
        mnr[id] = inf;
    }   

    void pullup(int id, int l, int r) {
        res[id] = max(res[id << 1], res[id << 1 | 1]);
        mxl[id] = max(mxl[id << 1], mxl[id << 1 | 1]);
        mnl[id] = min(mnl[id << 1], mnl[id << 1 | 1]);
    }

    void posupd(int id, int l, int r, int pos, ii d) {
        if(pos < l || pos > r) return;
        if(l == r) {
            mxl[id] = d.fi;
            mnl[id] = d.se;
            return;
        }
        int mid = l + r >> 1;
        pushdown(id, l, r);

        posupd(id << 1, l, mid, pos, d);
        posupd(id << 1 | 1, mid + 1, r, pos, d);

        pullup(id, l, r);
    }

    void ranupd(int id, int l, int r, int u, int v, ii d) {
        if(l > v || r < u) return;
        if(l >= u && r <= v) {
            apply(id, d);
            return;
        }
        int mid = l + r >> 1;
        pushdown(id, l, r);

        ranupd(id << 1, l, mid, u, v, d);
        ranupd(id << 1 | 1, mid + 1, r, u, v, d);

        pullup(id, l, r);
    }

    int get(int id, int l, int r, int u, int v) {
        if(l > v || r < u) return -inf;
        if(l >= u && r <= v) return res[id];

        int mid = l + r >> 1;
        pushdown(id, l, r);

        return max(get(id << 1, l, mid, u, v), get(id << 1 | 1, mid + 1, r, u, v));
    }
} smt;

signed main() {
    if(fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout); 
    }
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    cin >> n;
    FOR(i, 1, n) {
        cin >> h[i] >> a[i] >> b[i];
        if(i + a[i] <= n) {
            open[i + a[i]].pb(i);
            close[min(n, i + b[i])].pb(i);
        }
    }
    cin >> q;
    FOR(i, 1, q) {
        int l, r;
        cin >> l >> r;
        qu[r].pb({l, i});
    }

    smt.init();

    FOR(i, 1, n) {
        for(int id : open[i]) {
            smt.posupd(1, 1, n, id, {h[id], h[id]});
        }

        if(i - a[i] >= 1) {
            smt.ranupd(1, 1, n, max(1, i - b[i]), i - a[i], {h[i], h[i]});
        }

        for(ii x : qu[i]) {
            ans[x.se] = smt.get(1, 1, n, x.fi, i - 1);
        }

        for(int id : close[i]) {
            smt.posupd(1, 1, n, id, {-inf, inf});
        }
    }

    FOR(i, 1, q) cout << (ans[i] == -inf ? -1 : ans[i]) << '\n';
}

Compilation message (stderr)

antennas.cpp: In function 'int main()':
antennas.cpp:109:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  109 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
antennas.cpp:110:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  110 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
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