Submission #334518

#	Time	Username	Problem	Language	Result	Execution time	Memory
334518		rocks03	Finding Routers (IOI20_routers)	C++14	95.01 / 100	2 ms	492 KiB

routers

#pragma GCC target("avx2")
#pragma GCC optimization("O3")
#pragma GCC optimization("unroll-loops")
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define ff first
#define ss second
#define pb push_back
#define SZ(x) ((int)(x).size())
#define all(x) x.begin(), x.end()
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

int use_detector(int x);

vector<int> find_routers(int l, int n, int q){
    vector<int> ans(n), mx(n + 1, 0), mn(n + 1, l + 1);
    ans[0] = 0;
    for(int i = 1; i < n; i++){
        int ql = mx[i - 1], qr = mn[i + 1];
        while(qr - ql > 1){
            int qm = (ql + qr) / 2;
            int id = use_detector(qm);
            if(id < i){
                ql = qm;
            } else{
                qr = qm;
            }
            mn[id] = min(mn[id], qm);
            mx[id] = max(mx[id], qm);
        }
        ans[i] = 2*(ql - ans[i-1]) + ans[i-1];
        mx[i] = max(mx[i], ans[i] + 1);
    }
    return ans;
}

Compilation message (stderr)

routers.cpp:2: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
    2 | #pragma GCC optimization("O3")
      | 
routers.cpp:3: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
    3 | #pragma GCC optimization("unroll-loops")
      |

• Subtask 1: 16 / 16
• Subtask 2: 21 / 21
• Subtask 3: 23 / 23
• Subtask 4: 35.007999999999996 / 40