Submission #1108221

#	Time	Username	Problem	Language	Result	Execution time	Memory
1108221		InvMOD	Index (COCI21_index)	C++14	110 / 110	372 ms	33112 KiB

index

#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define gcd __gcd
#define sz(v) (int) v.size()
#define pb push_back
#define pi pair<int,int>
#define all(v) (v).begin(), (v).end()
#define compact(v) (v).erase(unique(all(v)), (v).end())
#define FOR(i, a, b) for(int i = (a); i <= (b); i++)
#define dbg(x) "[" #x " = " << (x) << "]"
///#define int long long

using ll = long long;
using ld = long double;
using ull = unsigned long long;

template<typename T> bool ckmx(T& a, const T& b){if(a < b) return a = b, true; return false;}
template<typename T> bool ckmn(T& a, const T& b){if(a > b) return a = b, true; return false;}

const int N = 2e5+5;
const ll MOD = 1e9+7;
const ll INF = 1e18;



int n, q, a[N], b[N];

int ql[N], qr[N], bit[N];

pair<int,int> Q[N];
vector<int> md[N];

void update(int p, int val){
    for(; p <= n; p += p&-p) bit[p] += val;
    return;
}

int get(int p){
    int res = 0;
    for(; p; p -= p&-p) res += bit[p];
    return res;
}

int get_range(int l, int r){
    return get(r) - get(l-1);
}

void solve()
{
    cin >> n >> q;
    for(int i = 1; i <= n; i++){
        cin >> a[i];
        b[i] = i;
    }

    for(int i = 1; i <= q; i++){
        cin >> Q[i].first >> Q[i].second;
        ql[i] = 1, qr[i] = 2e5+1;
    }

    sort(b+1, b+1+n, [&](int x, int y){
            return a[x] > a[y];
    });

    bool changed = true;
    while(changed){

        changed = false;
        for(int i = 1; i <= q; i++){
            if(ql[i]+1 < qr[i]){
                changed = true;
                md[ql[i]+qr[i]>>1].push_back(i);
            }
        }

        for(int i = 2e5, j = 1; i >= 1; i--){
            while(a[b[j]] >= i) update(b[j], 1), j++;

            while(md[i].size()){
                int id = md[i].back();

                int l = Q[id].first, r = Q[id].second;
                if(get_range(l, r) >= i) ql[id] = i;
                else{
                    qr[id] = i;
                }

                md[i].pop_back();
            }
        }

        for(int i = 1; i <= n; i++) bit[i] = 0;
    }

    for(int i = 1; i <= q; i++) cout << ql[i] <<"\n";
}

signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    #define name "InvMOD"
    if(fopen(name".INP", "r")){
        freopen(name".INP","r",stdin);
        freopen(name".OUT","w",stdout);
    }

    int t = 1; //cin >> t;
    while(t--) solve();
    return 0;
}

Compilation message (stderr)

index.cpp: In function 'void solve()':
index.cpp:75:25: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   75 |                 md[ql[i]+qr[i]>>1].push_back(i);
      |                    ~~~~~^~~~~~
index.cpp: In function 'int main()':
index.cpp:109:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  109 |         freopen(name".INP","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
index.cpp:110:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  110 |         freopen(name".OUT","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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