Submission #1024051

#	Time	Username	Problem	Language	Result	Execution time	Memory
1024051		kustizus	Index (COCI21_index)	C++17	110 / 110	1428 ms	16004 KiB

index

// #pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx2,fma,bmi2,popcnt,lzcnt")
#include <bits/stdc++.h>
#define int long long
using namespace std;
mt19937_64 rnd(chrono::high_resolution_clock::now().time_since_epoch().count());
const int N=2e5;
int n,q,block,a[N+5],ans[N+5],FT[N+5];
struct Node{
    int l,r,idx;
};
bool comp(Node a, Node b){
    if (a.l/block!=b.l/block) return a.l/block<b.l/block;
    return a.r<b.r;
};
void Update(int pos, int val){
    for (;pos<=N;pos+=pos&(-pos)) FT[pos]+=val;
}
int Get(int pos){
    int val=0;
    for (;pos;pos-=pos&(-pos)) val+=FT[pos];
    return val;
}
vector <Node> v;
void Solve(){
    cin>>n>>q;
    for (int i=1;i<=n;++i) cin>>a[i];
    for (int i=1;i<=q;++i){
        int l,r;
        cin>>l>>r;
        v.push_back({l,r,i});
    }
    block=sqrt(n);
    sort(v.begin(),v.end(),comp);
    int x=1,y=0;
    for (int i=0;i<q;++i){
        while (x<v[i].l){
            Update(a[x],-1);
            ++x;
        }
        while (x>v[i].l){
            --x;
            Update(a[x],1);
        }
        while (y<v[i].r){
            ++y;
            Update(a[y],1);
        }
        while (y>v[i].r){
            Update(a[y],-1);
            --y;
        }
        int left=1,right=y-x+1;
        while (left<right){
            int md=left+right>>1;
            if (Get(N)-Get(md)>=md+1) left=md+1;
            else right=md;
        }
        ans[v[i].idx]=left;
    }
    for (int i=1;i<=q;++i) cout<<ans[i]<<"\n";
}
signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    // freopen ("FILE.INP","r",stdin);
    // freopen ("FILE.OUT","w",stdout);
    int t=1;
    // cin>>t;
    while (t--) Solve();
    cerr<<"\nTIME: "<<1000*clock()/CLOCKS_PER_SEC<<"ms\n";
}

Compilation message (stderr)

index.cpp: In function 'void Solve()':
index.cpp:55:24: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   55 |             int md=left+right>>1;
      |                    ~~~~^~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 50 / 50