Submission #550582

#	Time	Username	Problem	Language	Result	Execution time	Memory
550582		jeroenodb	Two Antennas (JOI19_antennas)	C++14	100 / 100	460 ms	40148 KiB

antennas

#include "bits/stdc++.h"
using namespace std;
#define all(x) begin(x),end(x)
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { string sep; for (const T &x : v) os << sep << x, sep = " "; return os; }
#define debug(a) cerr << "(" << #a << ": " << a << ")\n";
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> pi;
const int mxN = 1e5+1, oo = 1e9;
vi H;
struct segtree {
    struct node {
        // what do I need?

        int mxans=-1;
        array<int,2> h = {oo,-oo}, lazy = {oo,-oo};
        node() {}
    };
    vector<node> seg;
    int n,ptwo;
    segtree(int nn) {
        n=nn,ptwo=1;
        while(ptwo<n) ptwo*=2;
        seg.resize(2*ptwo);
    }
    void puttag(int i, array<int,2> lazy) {
        auto& v = seg[i];
        v.mxans = max({v.mxans,lazy[1]-v.h[0],v.h[1]-lazy[0]});
        v.lazy[0] = min(v.lazy[0],lazy[0]);
        v.lazy[1] = max(v.lazy[1],lazy[1]);
    }
    void pull(int i) {
        auto& v = seg[i], &l = seg[i*2], &r = seg[i*2+1];
        v.mxans = max(l.mxans,r.mxans);
        v.h[0] = min(l.h[0],r.h[0]);
        v.h[1] = max(l.h[1],r.h[1]);
    }
    void push(int i) { // TODO!
        auto& v = seg[i];
        puttag(i*2,v.lazy);
        puttag(i*2+1,v.lazy);
        v.lazy = {oo,-oo};
    }
    int get(int i, int l, int r, int ql, int qr) {
        if(qr<l or r<ql) return -1;
        if(ql<=l and r<=qr) {
            return seg[i].mxans;
        }
        int mid = (l+r)/2;
        push(i);
        auto res = max(get(i*2,l,mid,ql,qr),get(i*2+1,mid+1,r,ql,qr)); // TODO
        pull(i);
        return res;
    }
    void set(int i, int l, int r, int ql, int qr, int v) {
        if(qr<l or r<ql) return;
        if(ql<=l and r<=qr) {
            puttag(i,{v,v}); // correct?
            return;
        }
        int mid = (l+r)/2;
        push(i);
        set(i*2,l,mid,ql,qr,v),set(i*2+1,mid+1,r,ql,qr,v);
        pull(i);
    }
    void set2(int i, int l, int r, int q) {
        if(q<l or r<q) return;
        if(l==q and r==q) {
            if(seg[i].h[0]==oo) seg[i].h = {H[l],H[l]};
            else seg[i].h = {oo,-oo};
            return;
        }
        int mid = (l+r)/2;
        push(i);
        set2(i*2,l,mid,q),set2(i*2+1,mid+1,r,q);
        pull(i);
    }
    void set(int l, int r, ll v) {
        set(1,0,ptwo-1,l,r,v);
    }
    void set2(int i) {
        set2(1,0,ptwo-1,i);
    }
    int get(int l, int r) {
        return get(1,0,ptwo-1,l,r);
    }
    node& operator[](int i) {return seg[i+ptwo];}
    void build() {
        for(int i=ptwo-1;i>=1;--i) {
            pull(i);
        }
    }
};

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int n; cin >> n;
    H.resize(n);
    vi a(n),b(n);
    for(int i=0;i<n;++i) {
        cin >> H[i] >> a[i] >> b[i];
    }
    vvi activations(n+1);
    for(int i=0;i<n;++i) {
        activations[min(n,i+a[i])].push_back(i);
        activations[min(n,i+b[i]+1)].push_back(i);
    }
    int Q; cin >> Q;
    vector<array<int,2>> qs(Q);
    vvi ids(n);
    {int id=0;
    for(auto& [l,ans] : qs) {
        int r; cin >> l >> r;
        --l,--r;
        ids[r].push_back(id++);
    }
    }
    segtree seg(n);
    seg.build();
    for(int j=0;j<n;++j) {
        int l = max(0,j-b[j]), r = max(-1,j-a[j]);
        for(auto i : activations[j]) 
            seg.set2(i);
        if(r>=0) {
            seg.set(l,r,H[j]);
        }
        for(int id : ids[j]) {
            int lb = qs[id][0];
            qs[id][1] = seg.get(lb,j);
        }
    }
    for(auto [l,ans] : qs) {
        cout << ans << '\n';
    }
    
}

Compilation message (stderr)

antennas.cpp: In function 'int main()':
antennas.cpp:115:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  115 |     for(auto& [l,ans] : qs) {
      |               ^
antennas.cpp:135:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  135 |     for(auto [l,ans] : qs) {
      |              ^

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