174 lines
3.6 KiB
C++
174 lines
3.6 KiB
C++
/* Problem URL: https://codeforces.com/contest/954/problem/E */
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#include <bits/stdc++.h>
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#include <ext/pb_ds/assoc_container.hpp>
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#include <ext/pb_ds/tree_policy.hpp>
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using namespace std;
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using namespace __gnu_pbds;
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template <class T, class comp = less<>>
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using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
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#define V vector
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#define rmin(a, b) a = min(a, b)
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#define rmax(a, b) a = max(a, b)
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#define rep(i, lim) for (int i = 0; i < (lim); i++)
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#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
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#define repv(i, v) for (auto &i : (v))
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#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
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#define sortv(v) sort(v.begin(), v.end())
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#define all(v) (v).begin(), (v).end()
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using vi = vector<int>;
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using vvi = vector<vi>;
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using vvvi = vector<vvi>;
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using vvvvi = vector<vvvi>;
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using ll = long long;
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using vl = vector<ll>;
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using vvl = vector<vl>;
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using vvvl = vector<vvl>;
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using vvvvl = vector<vvvl>;
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template<class v>
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auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
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os << vec[0];
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for (size_t i = 1; i < vec.size(); i++) {
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os << ' ' << vec[i];
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}
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os << '\n';
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return os;
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}
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template<class v>
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auto operator>>(istream &is, vector<v> &vec)->istream& {
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for (auto &i : vec) {
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is >> i;
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}
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return is;
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}
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template<class v>
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auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
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for (auto &i : vec) {
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os << i[0];
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for (size_t j = 1; j < i.size(); j++) {
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os << ' ' << i[j];
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}
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os << '\n';
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}
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return os;
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}
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template<class v>
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auto operator>>(istream &is, vector<vector<v>> &vec)->istream& {
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for (auto &i : vec) {
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for (auto &j : i) {
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is >> j;
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}
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}
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return is;
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}
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int main()
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{
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ios::sync_with_stdio(false);
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cin.tie(nullptr);
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int n;
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long double t;
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cin >> n >> t;
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V<pair<long double, long double>> a(n);
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repv(i, a) {
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cin >> i.second;
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}
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repv(i, a) {
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cin >> i.first;
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}
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sort(all(a), [&](pair<long double, long double> &a, pair<long double, long double> &b) {
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if (a.first == b.first) {
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return a.second > b.second;
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}
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return a.first < b.first;
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});
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long double start = 0;
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long double test = 0;
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rep(i, n) {
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start += a[i].second;
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test += a[i].second * a[i].first;
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}
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if (test / start < t) {
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cout << "0\n";
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return 0;
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}
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long double low = 0;
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long double high = start;
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rep(i, 300) {
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long double mid = (high + low) / 2.0L;
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long double ans = 0;
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long double tmp = mid;
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long double total = 0;
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rep(i, n) {
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if (a[i].second >= tmp) {
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ans += tmp * a[i].first;
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total += tmp;
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break;
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}
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ans += a[i].second * a[i].first;
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total += a[i].second;
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tmp -= a[i].second;
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}
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ans /= total;
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// cout << high - low << ' ' << mid << ' ' << ans << '\n';
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if (ans <= t) {
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low = mid;
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continue;
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}
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high = mid;
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}
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long double tmp = low;
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long double total = 0;
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long double temp = 0;
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rep(i, n) {
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if (a[i].second >= tmp) {
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temp += tmp * a[i].first;
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total += tmp;
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break;
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}
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temp += a[i].second * a[i].first;
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total += a[i].second;
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tmp -= a[i].second;
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}
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temp /= total;
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// long double eps = 1e-9;
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// if (abs(t - temp) >= eps) {
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// cout << "0\n";
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// return 0;
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// }
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cout << setprecision(9) << low << '\n';
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}
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