oj.uz

Submission #801952

# Submission time Handle Problem Language Result Execution time Memory
801952 2023-08-02T08:40:25 Z ymm Seesaw (JOI22_seesaw) C++17
100 / 100
 45 ms 8012 KB 
#include <bits/stdc++.h>
#define Loop(x,l,r) for (ll x = (l); x < (r); ++x)
#define LoopR(x,l,r) for (ll x = (r)-1; x >= (l); --x)
typedef long long ll;
using namespace std;

const int N = 200'010;
double pos[N];
double sum;
int n;

vector<pair<double,double>> arr;
void make()
{
	double sum = ::sum;
	double m = sum/n;
	int p0 = 0, p1 = n-1;
	pos[n] = 2e9;
	auto cur_pair = [&]() {
		return pair<double,double>(sum/(p1-p0+1), (sum - pos[p0] + pos[p1+1])/(p1-p0+1));
	};
	arr = {cur_pair()};
	for (int cnt = n; p0 < p1; --cnt) {
		if ((sum-pos[p0])/(cnt-1) <= m) {
			sum -= pos[p0];
			++p0;
		} else {
			sum -= pos[p1];
			--p1;
		}
		arr.push_back(cur_pair());
	}
}

int main()
{
	cin.tie(0) -> sync_with_stdio(false);
	cin >> n;
	Loop (i,0,n) {
		ll x;
		cin >> x;
		pos[i] = x;
		sum += pos[i];
	}
	make();
	sort(arr.begin(), arr.end(), [](const pair<double,double> &a, const pair<double,double> &b){
		return a.second < b.second;
	});
	LoopR (i,0,arr.size()-1)
		arr[i].first = min(arr[i].first, arr[i+1].first);
	double m = sum/n;
	double ans = min(m - arr.front().first, arr.back().second - m);
	Loop (i,0,arr.size()-1)
		ans = min(ans, arr[i].second - arr[i+1].first);
	cout << fixed << setprecision(9);
	cout << ans << '\n';
}

Compilation message

seesaw.cpp: In function 'int main()':
seesaw.cpp:2:40: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<double, double> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    2 | #define Loop(x,l,r) for (ll x = (l); x < (r); ++x)
      |                                        ^
seesaw.cpp:53:2: note: in expansion of macro 'Loop'
   53 |  Loop (i,0,arr.size()-1)
      |  ^~~~

Subtask #1
1.0 / 1.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct

Subtask #2
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct

Subtask #3
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct

Subtask #4
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 35 ms 7936 KB Output is correct
13 Correct 34 ms 8012 KB Output is correct
14 Correct 42 ms 8004 KB Output is correct
15 Correct 35 ms 7948 KB Output is correct
16 Correct 45 ms 7940 KB Output is correct