Submission #206020

#	Time	Username	Problem	Language	Result	Execution time	Memory
206020		achibasadzishvili	Two Antennas (JOI19_antennas)	C++17	100 / 100	833 ms	59256 KiB

antennas

#include<bits/stdc++.h>
#define ll long long
#define f first
#define s second
#define pb push_back
#define N 200005
#define mp make_pair
using namespace std;
ll save[6*N],inf=1000000000000000,pown=1;
ll n,q,a[N],b[N],h[N],kl[N],kr[N],ans[N];
pair<ll,ll>t[6*N];
vector<ll>st[N],en[N];
vector<pair<ll,ll> >ge[N];
void updpoint(ll x,ll L,ll R,ll ind,ll val){
    if(L == R){
        if(val == -inf){
            t[x].s = -inf;
            save[x] = inf;
            return;
        }
        t[x].f = max(t[x].f , t[x].s - val);
        t[x].s = val;
        save[x] = val;
        return;
    }
    if(save[x] != inf){
        save[2 * x] = min(save[x] , save[2 * x]);
        t[2 * x].f = max(t[2 * x].f , t[2 * x].s - save[x]);
        save[2 * x + 1] = min(save[x] , save[2 * x + 1]);
        t[2 * x + 1].f = max(t[2 * x + 1].f , t[2 * x + 1].s - save[x]);
        save[x] = inf;
    }
    ll mid = (L + R) / 2;
    if(mid >= ind)updpoint(2 * x , L , mid , ind , val);
    else updpoint(2 * x + 1 , mid + 1 , R , ind , val);
    t[x].f = max(t[2 * x].f , t[2 * x + 1].f);
    t[x].s = max(t[2 * x].s , t[2 * x + 1].s);
}
void upd(ll x,ll L,ll R,ll l,ll r,ll val){
    if(L > r || R < l)return;
    if(L >= l && R <= r){
        save[x] = min(save[x] , val);
        t[x].f = max(t[x].f , t[x].s - save[x]);
        return;
    }
    if(save[x] != inf){
        save[2 * x] = min(save[x] , save[2 * x]);
        t[2 * x].f = max(t[2 * x].f , t[2 * x].s - save[x]);
        save[2 * x + 1] = min(save[x] , save[2 * x + 1]);
        t[2 * x + 1].f = max(t[2 * x + 1].f , t[2 * x + 1].s - save[x]);
        save[x] = inf;
    }
    ll mid = (L + R) / 2;
    upd(2 * x , L , mid , l , r , val);
    upd(2 * x + 1 , mid + 1 , R , l , r , val);
    t[x].f = max(t[2 * x].f , t[2 * x + 1].f);
    t[x].s = max(t[2 * x].s , t[2 * x + 1].s);
}
ll get(ll x,ll L,ll R,ll l,ll r){
    if(L > r || R < l)return -inf;
    if(L >= l && R <= r)return t[x].f;
    if(save[x] != inf){
        save[2 * x] = min(save[x] , save[2 * x]);
        t[2 * x].f = max(t[2 * x].f , t[2 * x].s - save[x]);
        save[2 * x + 1] = min(save[x] , save[2 * x + 1]);
        t[2 * x + 1].f = max(t[2 * x + 1].f , t[2 * x + 1].s - save[x]);
        save[x] = inf;
    }
    ll mid = (L + R) / 2;
    ll k1 = get(2 * x , L , mid , l , r);
    ll k2 = get(2 * x + 1 , mid + 1 , R , l , r);
    return max(k1 , k2);
}
void solve(){
    for(int i=1; i<=n; i++){
        st[i].clear();
        en[i].clear();
        ge[i].clear();
    }
    for(int i=1; i<=2 * pown; i++){
        save[i] = inf;
        t[i].f = -inf;
        t[i].s = -inf;
    }
    for(int i=1; i<=q; i++){
        ge[kr[i]].pb(mp(kl[i] , i));
    }
    for(int i=1; i<=n; i++){
        if(i + a[i] <= n)
            st[i + a[i]].pb(i);
        if(i + b[i] <= n)
            en[i + b[i]].pb(i);
    }
    
    for(int i=1; i<=n; i++){
        for(int j=0; j<st[i].size(); j++)
            updpoint(1 , 1 , pown , st[i][j] , h[st[i][j]]);
        ll l = 1 , r = 0;
        if(i - b[i] >= 1)l = i - b[i];
        if(i - a[i] >= 1)r = i - a[i];
        //cout << l << " " << r << " " << h[i] << '\n';
        if(r >= l)
            upd(1 , 1 , pown , l , r , h[i]);
        for(int j=0; j<ge[i].size(); j++){
            ll cur = get(1 , 1 , pown , ge[i][j].f , i);
            //cout << i << " " << ge[i][j].f << " " << i << " " << cur << '\n';
            ans[ge[i][j].s] = max(ans[ge[i][j].s] , cur);
        }
        for(int j=0; j<en[i].size(); j++)
            updpoint(1 , 1 , pown , en[i][j] , -inf);
    }
}
int main(){
    ios::sync_with_stdio(false);
    cin >> n;
    while(pown <= n)
        pown *= 2;
    for(int i=1; i<=n; i++){
        cin >> h[i] >> a[i] >> b[i];
    }
    
    cin >> q;
    
    for(int i=1; i<=q; i++){
        cin >> kl[i] >> kr[i];
        ans[i] = -1;
    }
    
    solve();
    for(int i=1; i<=n / 2; i++){
        swap(h[i] , h[n - i + 1]);
        swap(a[i] , a[n - i + 1]);
        swap(b[i] , b[n - i + 1]);
    }
    
    for(int i=1; i<=q; i++){
        ll f = kl[i];
        kl[i] = n - kr[i] + 1;
        kr[i] = n - f + 1;
    }
    
    solve();
    
    for(int i=1; i<=q; i++)
        cout << ans[i] << '\n';
    
    
    
    return 0;
}

Compilation message (stderr)

antennas.cpp: In function 'void solve()':
antennas.cpp:96:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j=0; j<st[i].size(); j++)
                      ~^~~~~~~~~~~~~
antennas.cpp:104:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j=0; j<ge[i].size(); j++){
                      ~^~~~~~~~~~~~~
antennas.cpp:109:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j=0; j<en[i].size(); j++)
                      ~^~~~~~~~~~~~~

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