oj.uz

Submission #1055513

# Submission time Handle Problem Language Result Execution time Memory
1055513 2024-08-12T20:39:59 Z juliany2 Seesaw (JOI22_seesaw) C++17
100 / 100
 53 ms 13776 KB 
#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define all(x) (x).begin(), (x).end()

// path from (1, n) to any (i, i)
// as long as all diags have at least one valid theres always a valid path
// can connect any two of these points with a right/down path, which is monotic increasing

int main() {
    cin.tie(0)->sync_with_stdio(false);

    int n;
    cin >> n;

    vector<ll> a(n + 1), pref(n + 1);
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        pref[i] = pref[i - 1] + a[i];
    }

    double avg = (double) pref[n] / n;

    vector<pair<double, int>> b;
    b.push_back({avg, n});

    for (int len = 1; len < n; len++) {
        int lo = len, hi = n;
        while (lo < hi) {
            int mid = (lo + hi + 1) / 2;

            if ((double) (pref[mid] - pref[mid - len]) / len < avg)
                lo = mid;
            else
                hi = mid - 1;
        }

        b.push_back({(double) (pref[lo] - pref[lo - len]) / len, len});
        b.push_back({(double) (pref[lo + 1] - pref[lo + 1 - len]) / len, len});
    }

    sort(all(b));

    vector<int> cnt(n + 1);
    int valid = 0;

    double ans = 1e18;
    int r = -1;
    for (int l = 0; l < b.size(); l++) {
        while (r + 1 < b.size() && valid < n) {
            r++;
            if (!cnt[b[r].second]++)
                valid++;
        }

        if (valid == n)
            ans = min(ans, b[r].first - b[l].first);

        if (!--cnt[b[l].second])
            valid--;
    }

    cout << fixed << setprecision(15) << ans << '\n';

    return 0;
}

Compilation message

seesaw.cpp: In function 'int main()':
seesaw.cpp:49:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<double, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |     for (int l = 0; l < b.size(); l++) {
      |                     ~~^~~~~~~~~~
seesaw.cpp:50:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<double, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 |         while (r + 1 < b.size() && valid < n) {
      |                ~~~~~~^~~~~~~~~~

Subtask #1
1.0 / 1.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 456 KB Output is correct

Subtask #2
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 456 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct

Subtask #3
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 456 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 1 ms 604 KB Output is correct
10 Correct 1 ms 604 KB Output is correct
11 Correct 1 ms 604 KB Output is correct

Subtask #4
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 456 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 1 ms 604 KB Output is correct
10 Correct 1 ms 604 KB Output is correct
11 Correct 1 ms 604 KB Output is correct
12 Correct 51 ms 13764 KB Output is correct
13 Correct 53 ms 13768 KB Output is correct
14 Correct 50 ms 13776 KB Output is correct
15 Correct 50 ms 13776 KB Output is correct
16 Correct 51 ms 13768 KB Output is correct