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Submission #731611

# Submission time Handle Problem Language Result Execution time Memory
731611 2023-04-27T16:35:28 Z PoonYaPat Radio Towers (IOI22_towers) C++17
17 / 100
 1561 ms 90076 KB 
#include "towers.h"
#include <bits/stdc++.h>
using namespace std;
typedef pair<int,int> pii;

int R[100010],L[100010],h[100010],n,s[1<<18];
vector<pii> v;

struct ss {
    int mmin,mmax,sl,sr;
} sg[1<<18]; // i<j -> sl = j-i, sr=i-j

ss merge(ss l, ss r) {
    if (l.mmin==-1 && r.mmin==-1) return {-1,0,0,0};
    if (l.mmin==-1) return r;
    if (r.mmin==-1) return l;

    ss ans;
    ans.mmax=max(l.mmax,r.mmax);
    ans.mmin=min(l.mmin,r.mmin);
    ans.sl=max({l.sl,r.sl,r.mmax-l.mmin});
    ans.sr=max({l.sr,r.sr,l.mmax-r.mmin});
    return ans;
}

void build_sg(int l, int r, int idx) {
    if (l==r) sg[idx]={h[l],h[l],0,0};
    else {
        int mid=(l+r)/2;
        build_sg(l,mid,2*idx);
        build_sg(mid+1,r,2*idx+1);
        sg[idx]=merge(sg[2*idx],sg[2*idx+1]);
    }
}

ss query_sg(int l, int r, int idx, int x, int y) {
    if (x>r || y<l) return {-1,0,0,0};
    if (x<=l && r<=y) return sg[idx];
    int mid=(l+r)/2;
    return merge(query_sg(l,mid,2*idx,x,y),query_sg(mid+1,r,2*idx+1,x,y));
}

struct node {
    int mmin,mmax,cnt;
    node *l, *r;

    node() : mmin(INT_MAX), mmax(-INT_MAX), cnt(0), l(NULL), r(NULL) {}

    node(int val) : mmin(val), mmax(val), cnt(1), l(NULL), r(NULL) {}

    node(node *L, node *R) : mmin(INT_MAX), mmax(-INT_MAX), cnt(0) , r(R), l(L) {
        if (L) {
            mmin=min(L->mmin,mmin);
            mmax=max(L->mmax,mmax);
            cnt+=L->cnt;
        }

        if (R) {
            mmin=min(R->mmin,mmin);
            mmax=max(R->mmax,mmax);
            cnt+=R->cnt;
        }
    }
};
typedef pair<int,node*> pin;
vector<pin> arr;

struct N {
    int mmin,mmax,cnt;
};

node* build(int l, int r) {
    if (l==r) return new node();
    int mid=(l+r)/2;
    return new node(build(l,mid),build(mid+1,r));
}

node* update(int l, int r, int x, node* pnode) {
    if (x>r || x<l) return pnode;
    if (l==r) return new node(l);
    int mid=(l+r)/2;
    return new node(update(l,mid,x,pnode->l),update(mid+1,r,x,pnode->r));
}

N query(int l, int r, int x, int y, node *pnode) {
    if (x>r || y<l) return {INT_MAX,-INT_MAX,0};
    if (x<=l && r<=y) return {pnode->mmin,pnode->mmax,pnode->cnt};
    int mid=(l+r)/2;
    N ans,L=query(l,mid,x,y,pnode->l),R=query(mid+1,r,x,y,pnode->r);
    ans.mmax=max(L.mmax,R.mmax);
    ans.mmin=min(L.mmin,R.mmin);
    ans.cnt=L.cnt+R.cnt;
    return ans;
}

void build_s(int l, int r, int idx) {
    if (l==r) s[idx]=h[l];
    else {
        int mid=(l+r)/2;
        build_s(l,mid,2*idx);
        build_s(mid+1,r,2*idx+1);
        s[idx]=max(s[2*idx],s[2*idx+1]);
    }
}

int query_s(int l, int r, int idx, int x, int y) {
    if (x>r || y<l) return 0;
    if (x<=l && r<=y) return s[idx];
    int mid=(l+r)/2;
    return max(query_s(l,mid,2*idx,x,y),query_s(mid+1,r,2*idx+1,x,y));
}

void init(int N, vector<int> H) {
    n=N;
    for (int i=0; i<n; ++i) h[i+1]=H[i];

    L[1]=0;
    for (int i=2; i<=n; ++i) {
        int idx=i-1;
        while (h[idx]>=h[i] && idx!=-1) idx=L[idx];
        L[i]=idx;
    }

    R[n]=n+1;
    for (int i=n-1; i>=1; --i) {
        int idx=i+1;
        while (h[idx]>=h[i] && idx!=-1) idx=R[idx];
        R[i]=idx;
    }

    build_s(1,n,1);
    build_sg(1,n,1);

    for (int i=1; i<=n; ++i) {
        int h1=-1,h2=-1;
        if (L[i]+1<=i-1) h1=query_s(1,n,1,L[i]+1,i-1);
        if (i+1<=R[i]-1) h2=query_s(1,n,1,i+1,R[i]-1);

        if (L[i]==0) h1=INT_MAX;
        if (R[i]==n+1) h2=INT_MAX;

        if (h1!=-1 && h2!=-1) v.push_back(pii(min(h1,h2)-h[i],i));
    }

    sort(v.begin(),v.end(),greater<pii>());

    arr.push_back(pin(INT_MAX,build(1,n)));

    for (int i=0; i<v.size(); ++i) {
        node* pnode=update(1,n,v[i].second,arr.back().second);
        if (arr.back().first==v[i].first) arr.pop_back();
        arr.push_back(pin(v[i].first,pnode));
    }
}

int max_towers(int Le, int Ri, int D) {
    ++Le; ++Ri;

    int l=0, r=arr.size()-1;
    while (l<r) {
        int mid=(l+r+1)/2;
        if (arr[mid].first>=D) l=mid;
        else r=mid-1;
    }

    N res=query(1,n,Le,Ri,arr[l].second);
    int cnt=res.cnt,mi=res.mmin,ma=res.mmax;
    assert(cnt>0);
    if (cnt==0) return 1;

    int LL=-1;
    if (mi!=Le && query_s(1,n,1,Le,mi-1)>=h[mi]+D) {
        l=Le; r=mi-1;
        while (l<r) {
            int mid=(l+r+1)/2;
            if (query_s(1,n,1,mid,mi-1)>=h[mi]+D) l=mid;
            else r=mid-1;
        }
        LL=l;
    }
    if (LL!=-1 && query_sg(1,n,1,Le,LL).sl>=D) ++cnt;

    int RR=-1;
    if (ma!=Ri && query_s(1,n,1,ma+1,Ri)>=h[ma]+D) {
        l=ma+1; r=Ri;
        while (l<r) {
            int mid=(l+r)/2;
            if (query_s(1,n,1,ma+1,mid)>=h[ma]+D) r=mid;
            else l=mid+1;
        }
        RR=l;
    }
    if (RR!=-1 && query_sg(1,n,1,RR,Ri).sr>=D) ++cnt;

    return cnt;
}

Compilation message

towers.cpp: In constructor 'node::node(node*, node*)':
towers.cpp:45:15: warning: 'node::r' will be initialized after [-Wreorder]
   45 |     node *l, *r;
      |               ^
towers.cpp:45:11: warning:   'node* node::l' [-Wreorder]
   45 |     node *l, *r;
      |           ^
towers.cpp:51:5: warning:   when initialized here [-Wreorder]
   51 |     node(node *L, node *R) : mmin(INT_MAX), mmax(-INT_MAX), cnt(0) , r(R), l(L) {
      |     ^~~~
towers.cpp: In function 'void init(int, std::vector<int>)':
towers.cpp:149:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  149 |     for (int i=0; i<v.size(); ++i) {
      |                   ~^~~~~~~~~

Subtask #1
0 / 4.0

# Verdict Execution time Memory Grader output
1 Runtime error 38 ms 18864 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 464 KB Output is correct
2 Correct 3 ms 976 KB Output is correct
3 Correct 3 ms 976 KB Output is correct
4 Correct 3 ms 1104 KB Output is correct
5 Correct 2 ms 1104 KB Output is correct
6 Correct 2 ms 1104 KB Output is correct
7 Correct 2 ms 1104 KB Output is correct
8 Runtime error 3 ms 1104 KB Execution killed with signal 6
9 Halted 0 ms 0 KB -

Subtask #3
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 464 KB Output is correct
2 Correct 3 ms 976 KB Output is correct
3 Correct 3 ms 976 KB Output is correct
4 Correct 3 ms 1104 KB Output is correct
5 Correct 2 ms 1104 KB Output is correct
6 Correct 2 ms 1104 KB Output is correct
7 Correct 2 ms 1104 KB Output is correct
8 Runtime error 3 ms 1104 KB Execution killed with signal 6
9 Halted 0 ms 0 KB -

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Runtime error 1059 ms 90076 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

Subtask #5
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 322 ms 10376 KB Output is correct
2 Correct 911 ms 45276 KB Output is correct
3 Correct 1241 ms 45368 KB Output is correct
4 Correct 1131 ms 59392 KB Output is correct
5 Correct 978 ms 59424 KB Output is correct
6 Correct 1295 ms 59384 KB Output is correct
7 Correct 1159 ms 59416 KB Output is correct
8 Correct 1434 ms 16760 KB Output is correct
9 Correct 1561 ms 16720 KB Output is correct
10 Correct 1450 ms 16848 KB Output is correct
11 Correct 1147 ms 16652 KB Output is correct
12 Correct 112 ms 45200 KB Output is correct
13 Correct 117 ms 59392 KB Output is correct
14 Correct 118 ms 59552 KB Output is correct
15 Correct 38 ms 16712 KB Output is correct
16 Correct 45 ms 16688 KB Output is correct
17 Correct 87 ms 43832 KB Output is correct
18 Correct 100 ms 45256 KB Output is correct
19 Correct 111 ms 45260 KB Output is correct
20 Correct 146 ms 59448 KB Output is correct
21 Correct 129 ms 59408 KB Output is correct
22 Correct 145 ms 59468 KB Output is correct
23 Correct 138 ms 59484 KB Output is correct
24 Correct 36 ms 16696 KB Output is correct
25 Correct 46 ms 16720 KB Output is correct
26 Correct 48 ms 16688 KB Output is correct
27 Correct 37 ms 16716 KB Output is correct
28 Correct 2 ms 976 KB Output is correct
29 Correct 2 ms 1104 KB Output is correct
30 Correct 2 ms 1104 KB Output is correct
31 Correct 1 ms 592 KB Output is correct
32 Correct 1 ms 592 KB Output is correct
33 Correct 1 ms 592 KB Output is correct
34 Correct 2 ms 976 KB Output is correct
35 Correct 2 ms 976 KB Output is correct
36 Correct 2 ms 1104 KB Output is correct
37 Correct 3 ms 1104 KB Output is correct
38 Correct 2 ms 1104 KB Output is correct
39 Correct 2 ms 1168 KB Output is correct
40 Correct 1 ms 592 KB Output is correct
41 Correct 1 ms 592 KB Output is correct
42 Correct 1 ms 592 KB Output is correct
43 Correct 1 ms 592 KB Output is correct

Subtask #6
0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 464 KB Output is correct
2 Correct 3 ms 976 KB Output is correct
3 Correct 3 ms 976 KB Output is correct
4 Correct 3 ms 1104 KB Output is correct
5 Correct 2 ms 1104 KB Output is correct
6 Correct 2 ms 1104 KB Output is correct
7 Correct 2 ms 1104 KB Output is correct
8 Runtime error 3 ms 1104 KB Execution killed with signal 6
9 Halted 0 ms 0 KB -

Subtask #7
0 / 23.0

# Verdict Execution time Memory Grader output
1 Runtime error 38 ms 18864 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -