Submission #1025405

#	Time	Username	Problem	Language	Result	Execution time	Memory
1025405		Thanhs	Index (COCI21_index)	C++14	110 / 110	534 ms	32884 KiB

index

#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#define int long long
// #define double long double
#define pb push_back
 
#define endl '\n'
#define fastIO ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
#define setmin(x, y) x = min((x), (y))
#define setmax(x, y) x = max((x), (y))
#define sqr(x) ((x) * (x))
#define fi first
#define se second
 
mt19937 hdp(chrono::high_resolution_clock::now().time_since_epoch().count());
int rand(int l, int r){return l + ((hdp() % (r - l + 1)) + r - l + 1) % (r - l + 1);}
 
const int N = 2e5 + 5;
const int mod = 1e9 + 7;
const int p = 31;

struct Query
{
    int l, r, lx, rx, m, cur;
}Q[N];

int n, q, a[N], bit[N];
vector<pair<int, int>> ops[N];

void upd(int i)
{
    for (; i <= 2e5; i+= i & -i)
        bit[i]++;
}

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

signed main()
{
    if (fopen("in.txt", "r")) {
        freopen("in.txt","r",stdin);
        freopen("out.txt","w",stdout);
    }
    fastIO
    cin >> n >> q;
    for (int i = 1; i <= n; i++)
        cin >> a[i];
    for (int i = 1; i <= q; i++)
    {
        cin >> Q[i].l >> Q[i].r; 
        Q[i].lx = 1, Q[i].rx = Q[i].r - Q[i].l + 2;
    }
    while (1)
    {
        bool changed = 0;
        for (int i = 1; i <= q; i++)
            if (Q[i].lx < Q[i].rx - 1)
            {
                Q[i].m = Q[i].lx + Q[i].rx >> 1;
                Q[i].cur = 0;
                ops[Q[i].l - 1].push_back({i, -1});
                ops[Q[i].r].push_back({i, 1});
            }
        memset(bit, 0, sizeof bit);
        ops[0].clear();
        for (int i = 1; i <= n; i++)
        {
            upd(a[i]);
            for (auto p : ops[i])
                Q[p.fi].cur += p.se * (get(2e5) - get(Q[p.fi].m - 1));
            ops[i].clear();
        }
        for (int i = 1; i <= q; i++)
            if (Q[i].lx < Q[i].rx - 1)
            {
                if (Q[i].cur >= Q[i].m)
                    Q[i].lx = Q[i].m;
                else
                    Q[i].rx = Q[i].m;
                changed = true;

            }
        if (!changed) break;
    }
    for (int i = 1; i <= q; i++)
        cout << Q[i].lx << endl;
}

Compilation message (stderr)

index.cpp: In function 'int main()':
index.cpp:67:34: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   67 |                 Q[i].m = Q[i].lx + Q[i].rx >> 1;
      |                          ~~~~~~~~^~~~~~~~~
index.cpp:49:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |         freopen("in.txt","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~
index.cpp:50:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |         freopen("out.txt","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

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