Submission #1201316

#	Time	Username	Problem	Language	Result	Execution time	Memory
1201316		AMel0n	Finding Routers (IOI20_routers)	C++20	100 / 100	1 ms	328 KiB

routers

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

typedef long long ll;
#define FOR(i,N) for(ll i = 0; i < N; i++)
#define all(x) (x).begin(), (x).end()
#define F first 
#define S second

#include "routers.h"

vector<int> x;
void solve(int l, int r, int il, int ir) {
    if (il >= ir) return; //  need 2 indexes for comparison
    if (l == r) {
        x[il] = l-1; // idk why i-1;
        // binary searching the first x[i] such that x[i] is the midpoint between p[i] and p[i+1]
        return ;
    }
    int m = (l+r)/2;
    int im = use_detector(m);
    solve(l, m, il, im);
    solve(m+1, r, im, ir);
}

vector<int> find_routers(int l, int n, int q) {
    x.resize(n);
    solve(1, l, 0, n-1);
    // incl, incl, incl, incl
    vector<int> res(n);
    for(int i = 1; i < n; i++) res[i] = (x[i-1]*2 - res[i-1]);
    // (res[i] + res[i-1]) / 2 = x[i-1]      
    return res;
}



// signed main() {
//     cin.tie(0); ios::sync_with_stdio(false);

// }

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