Submission #210733

#	Time	Username	Problem	Language	Result	Execution time	Memory
210733		mhy908	Two Antennas (JOI19_antennas)	C++14	100 / 100	847 ms	54748 KiB

antennas

#include <bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define sortvec(x) sort(all(x))
#define compress(x) x.erase(unique(all(x)), x.end())
using namespace std;
typedef long long LL;
typedef pair<int, int> pii;
typedef pair<LL, LL> pll;
typedef pair<int, LL> pil;
typedef pair<LL, int> pli;
const LL llinf=987654321987654321;
const int inf=2000000000;

struct SEGMENT_TREE{
    LL tree[800010], h[800010], lazy[800010];
    void init(){
        for(int i=1; i<800000; i++){
            tree[i]=lazy[i]=-llinf;
            h[i]=llinf;
        }
    }
    void propogate(int point){
        lazy[point*2]=max(lazy[point], lazy[point*2]);
        lazy[point*2+1]=max(lazy[point], lazy[point*2+1]);
        tree[point*2]=max(tree[point*2], lazy[point*2]-h[point*2]);
        tree[point*2+1]=max(tree[point*2+1], lazy[point*2+1]-h[point*2+1]);
        lazy[point]=-llinf;
    }
    void update(int point, int s, int e, int num, LL qu){
        if(s==e){
            h[point]=qu;
            lazy[point]=-llinf;
            return;
        }
        propogate(point);
        int mid=(s+e)/2;
        if(num<=mid)update(point*2, s, mid, num, qu);
        else update(point*2+1, mid+1, e, num, qu);
        tree[point]=max(tree[point*2], tree[point*2+1]);
        h[point]=min(h[point*2], h[point*2+1]);
    }
    void alter(int point, int s, int e, int a, int b, LL qu){
        if(e<a||s>b)return;
        if(a<=s&&e<=b){
            lazy[point]=max(lazy[point], qu);
            tree[point]=max(tree[point], qu-h[point]);
            return;
        }
        int mid=(s+e)/2;
        propogate(point);
        alter(point*2, s, mid, a, b, qu);
        alter(point*2+1, mid+1, e, a, b, qu);
        tree[point]=max(tree[point*2], tree[point*2+1]);
    }
    LL query(int point, int s, int e, int a, int b){
        if(e<a||s>b)return -llinf;
        if(a<=s&&e<=b)return tree[point];
        propogate(point);
        int mid=(s+e)/2;
        return max(query(point*2, s, mid, a, b), query(point*2+1, mid+1, e, a, b));
    }
}seg;

int n, q;
pii range[200010];
pii query[200010];
LL ans[200010], h[200010];

vector<pii> qu[200010], upd[200010];
void solve(){
    for(int i=1; i<=n; i++){
        qu[i].clear();
        upd[i].clear();
    }
    seg.init();
    for(int i=1; i<=n; i++){
        int t1=min(i+range[i].F, n+1);
        int t2=min(i+range[i].S, n)+1;
        upd[t1].pb(mp(i, 1));
        upd[t2].pb(mp(i, 0));
    }
    for(int i=1; i<=q; i++)qu[query[i].S].pb(mp(query[i].F, i));
    for(int i=1; i<=n; i++){
        for(auto j:upd[i]){
            if(j.S)seg.update(1, 1, n, j.F, h[j.F]);
            else seg.update(1, 1, n, j.F, llinf);
        }
        if(i-range[i].F>=1){
            seg.alter(1, 1, n, max(1, i-range[i].S), i-range[i].F, h[i]);
        }
        for(auto j:qu[i]){
            //printf("query %d : %lld\n", j.S, seg.query(1, 1, n, j.F, i));
            ans[j.S]=max(ans[j.S], seg.query(1, 1, n, j.F, i));
        }
    }
}
int main(){
    scanf("%d", &n);
    for(int i=1; i<=n; i++){
        scanf("%lld %d %d", &h[i], &range[i].F, &range[i].S);
    }
    scanf("%d", &q);
    for(int i=1; i<=q; i++){
        scanf("%d %d", &query[i].F, &query[i].S);
        ans[i]=-1;
    }
    solve();
    for(int i=1; i<=n; i++)h[i]=1000000000-h[i];
    solve();
    for(int i=1; i<=q; i++)printf("%lld\n", ans[i]);
}

Compilation message (stderr)

antennas.cpp: In function 'int main()':
antennas.cpp:102:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
antennas.cpp:104:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%lld %d %d", &h[i], &range[i].F, &range[i].S);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
antennas.cpp:106:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &q);
     ~~~~~^~~~~~~~~~
antennas.cpp:108:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &query[i].F, &query[i].S);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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