//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx,avx2,sse,sse2,sse3,ssse3,sse4,abm,popcnt,mmx")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef double db;
typedef long double ldb;
typedef complex<double> cd;
constexpr ll INF64 = 9'000'000'000'000'000'000, INF32 = 2'000'000'000, MOD = 1'000'000'007;
constexpr db PI = acos(-1);
constexpr bool IS_FILE = false, IS_TEST_CASES = false;
random_device rd;
mt19937 rnd32(rd());
mt19937_64 rnd64(rd());
template<typename T>
bool assign_max(T& a, T b) {
if (b > a) {
a = b;
return true;
}
return false;
}
template<typename T>
bool assign_min(T& a, T b) {
if (b < a) {
a = b;
return true;
}
return false;
}
template<typename T>
T square(T a) {
return a * a;
}
template<>
struct std::hash<pair<ll, ll>> {
ll operator() (pair<ll, ll> p) const {
return ((__int128)p.first * MOD + p.second) % INF64;
}
};
void solve() {
ll n;
cin >> n;
vector<ll> arr(n);
ll sum = 0;
for (ll i = 0; i < n; i++) {
cin >> arr[i];
sum += arr[i];
}
vector<tuple<ll, ll, ll>> now(1, make_tuple(sum, 0, n - 1));
double st = sum / (double)n;
double mi = st, ma = st;
vector<pair<double, double>> a;
for (ll j = 1; j < n; j++) {
vector<tuple<ll, ll, ll>> nnow;
for (auto[x, l, r] : now) {
nnow.emplace_back(x - arr[l], l + 1, r);
nnow.emplace_back(x - arr[r], l, r - 1);
}
now.clear();
sort(nnow.begin(), nnow.end());
for (ll i = 0; i <= nnow.size(); i++) {
if ((i == 0 || get<0>(nnow[i - 1]) / (double)(n - j) <= st) && (i == nnow.size() || get<0>(nnow[i]) / (double)(n - j) >= st)) {
if (i > 0) {
now.push_back(nnow[i - 1]);
}
if (i < nnow.size()) {
now.push_back(nnow[i]);
}
break;
}
}
if (now.size() == 1) {
assign_min(mi, get<0>(now[0]) / (double)(n - j));
assign_max(ma, get<0>(now[0]) / (double)(n - j));
continue;
}
a.emplace_back(get<0>(now[0]) / (double)(n - j), get<0>(now[1]) / (double)(n - j));
}
sort(a.begin(), a.end());
double ans = ma - min(mi, (a.empty() ? mi : a[0].first));
for (ll i = 0; i < n; i++) {
assign_max(ma, a[i].second);
assign_min(ans, ma - min(mi, (i + 1 < a.size() ? a[i].first : mi)));
}
cout << setprecision(20) << ans << '\n';
}
int main() {
if (IS_FILE) {
freopen("", "r", stdin);
freopen("", "w", stdout);
}
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
ll t = 1;
if (IS_TEST_CASES) {
cin >> t;
}
for (ll i = 0; i < t; i++) {
solve();
}
}
Compilation message
seesaw.cpp: In function 'void solve()':
seesaw.cpp:71:34: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::tuple<long long int, long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
71 | for (ll i = 0; i <= nnow.size(); i++) {
| ~~^~~~~~~~~~~~~~
seesaw.cpp:72:91: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::tuple<long long int, long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
72 | if ((i == 0 || get<0>(nnow[i - 1]) / (double)(n - j) <= st) && (i == nnow.size() || get<0>(nnow[i]) / (double)(n - j) >= st)) {
| ~~^~~~~~~~~~~~~~
seesaw.cpp:76:39: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::tuple<long long int, long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
76 | if (i < nnow.size()) {
| ~~^~~~~~~~~~~~~
seesaw.cpp:93:53: 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]
93 | assign_min(ans, ma - min(mi, (i + 1 < a.size() ? a[i].first : mi)));
| ~~~~~~^~~~~~~~~~
seesaw.cpp: In function 'int main()':
seesaw.cpp:100:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
100 | freopen("", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~
seesaw.cpp:101:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
101 | freopen("", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
512 KB |
Output is correct |
| 2 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
512 KB |
Output is correct |
| 2 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
512 KB |
Output is correct |
| 2 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
512 KB |
Output is correct |
| 2 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
