Submission #883565

#	Time	Username	Problem	Language	Result	Execution time	Memory
883565		kongum	Finding Routers (IOI20_routers)	C++17	48.79 / 100	2 ms	1112 KiB

routers

#include <bits/stdc++.h>
#include "routers.h"

#define fi first
#define se second
#define all(a) (a).begin(), (a).end()

using namespace std;
using pii = pair<int, int>;
using ti3 = tuple<int, int, int>;

static int l, n, q;
static std::vector<int> p;
static std::vector<int> answer;
static int queries = 0;

const int MAX = 100010;
int arr[MAX], fir[MAX], cnt[MAX], res[MAX];


int lowerBound(int lo, int hi, int tar) { // tar + 1반환
    while (lo + 1 < hi) {
        int mid = (lo + hi) / 2;
        int chk = use_detector(mid);
        if (chk < tar) lo = mid;
        else hi = mid;
        
    }
    return hi;
}

void divide(int lo, int hi) {
    int mid = (lo + hi) / 2;
    int tar = use_detector(mid);
    int lft = lowerBound(lo, hi, tar);
    int rgt = lowerBound(lo, hi, tar + 1) - 1;
    arr[lft] = tar;
    arr[rgt] = tar;

    if (lo + 1 < lft) divide(lo, lft - 1);
    if (rgt + 1 < hi) divide(rgt, hi);
}

std::vector<int> find_routers(int l, int n, int q) {
    for (int i = 0; i < MAX; i++) arr[i] = -1;
    divide(-1, l + 1);

    for (int i = 1; i < l; i++) arr[i] = max(arr[i], arr[i - 1]);
    for (int i = 0; i < l + 1; i++) {
        if (arr[i] >= 0) cnt[arr[i]]++;
        if (i >= 1 && arr[i] > arr[i - 1]) fir[arr[i]] = i;
    }
    fir[0] = 0;
    res[0] = 0;

    for (int i = 1; i < n; i++) {
        res[i] = res[i - 1] + (cnt[i - 1] - 1) * 2;
        cnt[i] -= cnt[i - 1] - 2;
    }
    vector<int> v;
    for (int i = 0; i < n; i++) v.push_back(res[i]);

    return v;
}

Compilation message (stderr)

routers.cpp:15:12: warning: 'queries' defined but not used [-Wunused-variable]
   15 | static int queries = 0;
      |            ^~~~~~~
routers.cpp:12:18: warning: 'q' defined but not used [-Wunused-variable]
   12 | static int l, n, q;
      |                  ^
routers.cpp:12:15: warning: 'n' defined but not used [-Wunused-variable]
   12 | static int l, n, q;
      |               ^
routers.cpp:12:12: warning: 'l' defined but not used [-Wunused-variable]
   12 | static int l, n, q;
      |            ^

• Subtask 1: 16 / 16
• Subtask 2: 21 / 21
• Subtask 3: 0 / 23
• Subtask 4: 11.792 / 40