Submission #769145

#	Time	Username	Problem	Language	Result	Execution time	Memory
769145		Dan4Life	Dancing Elephants (IOI11_elephants)	C++17	26 / 100	9025 ms	2380 KiB

elephants

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) a.begin(),a.end()
const int mxN = (int)5e4+10;
const int B = 240;
int n, L, x[mxN];
using ar = array<int,3>;

struct Block{
    set<int> S;
    set<ar>S2;
    Block(){}
    void recalc(){
        S2.clear();
        auto itr = end(S);
        while(itr!=begin(S)){ itr--;
            auto it2 = S2.lower_bound({*itr+L+1,-1,-1});
            if(it2==end(S2)) S2.insert({*itr,1,*itr+L+1});
            else S2.insert({*itr,(*it2)[1]+1, (*it2)[2]});
        }
    }
    Block(set<int> XD){
        S.swap(XD); recalc();
    }
    void add(int x){
        if(S.count(x)) return;
        S.insert(x); recalc();
    }

    void rem(int x){
        if(!S.count(x)) return;
        S.erase(x); recalc();
    }
};
vector<Block> bl;

void combine(int i, int j){
    if(i>j) swap(i,j);
    auto S = bl[i].S, S2 = bl[j].S;
    if(sz(S)<sz(S2)) S.swap(S2);
    for(auto u : S2) S.insert(u);
    bl.erase(begin(bl)+j);
    bl.erase(begin(bl)+i);
    bl.insert(begin(bl)+i,Block(S));
} 

void divide(int i){
    auto S2 = bl[i].S;
    set<int> S1; S1.clear();
    int xd = sz(S2); xd/=2;
    while(xd--){
        auto cur = *begin(S2);
        S1.insert(cur); S2.erase(cur);
    }
    bl.erase(begin(bl)+i);
    bl.insert(begin(bl)+i,Block(S2));
    bl.insert(begin(bl)+i,Block(S1));
}

void init(int N, int l, int X[]){
    bl.pb({}); L = l; n = N;
    for(int i = 0; i < n; i++){
        x[i] = X[i]; bl[sz(bl)-1].add(x[i]);
        if(sz(bl[sz(bl)-1].S)>B) divide(sz(bl)-1);
    }
}

int update(int p, int y){
    for(int i = 0; i < sz(bl); i++){
        if(bl[i].S.count(x[p])){ bl[i].rem(x[p]); 
            while(i and sz(bl[i].S)+sz(bl[i-1].S) <= B) combine(i-1,i),i--;
            while(i<sz(bl)-1 and sz(bl[i].S)+sz(bl[i+1].S) <= B) combine(i,i+1),i++;
            break;
        }
    }
    x[p] = y;
    for(int i = 0; i < sz(bl); i++){
        if(i==sz(bl)-1 or *(--end(bl[i].S)) >= x[p]){
            bl[i].add(x[p]); if(sz(bl[i].S)>B) divide(i); break;
        }
    }
    int ans = 0, pos = 0;
    for(Block cur : bl){
        auto S = cur.S; auto S2 = cur.S2;
        if(*(--end(S))<pos) continue;
        auto itr = *S2.lower_bound({pos,-1,-1});
        ans+=itr[1], pos = itr[2];
    }
    return ans;
}

• Subtask 1: 10 / 10
• Subtask 2: 16 / 16
• Subtask 3: 0 / 24
• Subtask 4: 0 / 47
• Subtask 5: 0 / 3