My submission gives WA without using `cout<<fixed<<setprecision`. Since the median needs atmost 1 decimal place of precision, this feels weird. Any explanations?↵
↵
<spoiler summary="Code which will give WA on removing fixedprecision">↵
↵
~~~~~↵
#include <bits/stdc++.h>↵
// #include <ext/pb_ds/assoc_container.hpp>↵
// #include <ext/pb_ds/tree_policy.hpp>↵
↵
// using namespace __gnu_pbds;↵
↵
// template <class T>↵
// using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;↵
↵
using namespace std;↵
↵
template <class X, class Y>↵
ostream &operator<<(ostream &os, pair<X, Y> const &p)↵
{↵
return os << "(" << p.first << ", " << p.second << ") ";↵
}↵
template <class Ch, class Tr, class Container>↵
basic_ostream<Ch, Tr> &operator<<(basic_ostream<Ch, Tr> &os, Container const &x)↵
{↵
os << "[ ";↵
for (auto &y : x)↵
os << y << ", ";↵
return os << "]\n";↵
}↵
↵
#define int long long↵
#define len(a) (int)a.size()↵
const long long INF = 1e18;↵
const double EPS = 1e-9;↵
const int di[8] = {1, 0, -1, 0, 1, -1, -1, 1};↵
const int dj[8] = {0, 1, 0, -1, 1, 1, -1, -1};↵
// dp?, graph?, bs on answer?, compress/sort queries?, stupid observation?↵
int solve_case()↵
{↵
int n, m;↵
cin >> n >> m;↵
vector<int> a(n);↵
for (int i = 0; i < n; i++)↵
cin >> a[i];↵
double ans = 0;↵
vector<int> rest;↵
sort(a.begin(), a.end());↵
for (int i = 0; i < n; i++)↵
{↵
if (i < n - m + 1)↵
rest.push_back(a[i]);↵
else↵
ans += a[i];↵
}↵
int k = len(rest);↵
ans += (rest[(k - 1) / 2] + rest[k / 2]) / 2.0;↵
cout << ans << '\n';↵
return 0;↵
}↵
↵
int32_t main()↵
{↵
ios_base::sync_with_stdio(0);↵
cin.tie(0);↵
int t = 1;↵
cin >> t;↵
cout << fixed << setprecision(12);↵
for (int _ = 1; _ <= t; _++)↵
{↵
cout << "Case #" << _ << ": ";↵
solve_case();↵
}↵
return 0;↵
}↵
~~~~~↵
↵
↵
</spoiler>↵
↵
↵
<spoiler summary="Code which will give WA on removing fixedprecision">↵
↵
~~~~~↵
#include <bits/stdc++.h>↵
// #include <ext/pb_ds/assoc_container.hpp>↵
// #include <ext/pb_ds/tree_policy.hpp>↵
↵
// using namespace __gnu_pbds;↵
↵
// template <class T>↵
// using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;↵
↵
using namespace std;↵
↵
template <class X, class Y>↵
ostream &operator<<(ostream &os, pair<X, Y> const &p)↵
{↵
return os << "(" << p.first << ", " << p.second << ") ";↵
}↵
template <class Ch, class Tr, class Container>↵
basic_ostream<Ch, Tr> &operator<<(basic_ostream<Ch, Tr> &os, Container const &x)↵
{↵
os << "[ ";↵
for (auto &y : x)↵
os << y << ", ";↵
return os << "]\n";↵
}↵
↵
#define int long long↵
#define len(a) (int)a.size()↵
const long long INF = 1e18;↵
const double EPS = 1e-9;↵
const int di[8] = {1, 0, -1, 0, 1, -1, -1, 1};↵
const int dj[8] = {0, 1, 0, -1, 1, 1, -1, -1};↵
// dp?, graph?, bs on answer?, compress/sort queries?, stupid observation?↵
int solve_case()↵
{↵
int n, m;↵
cin >> n >> m;↵
vector<int> a(n);↵
for (int i = 0; i < n; i++)↵
cin >> a[i];↵
double ans = 0;↵
vector<int> rest;↵
sort(a.begin(), a.end());↵
for (int i = 0; i < n; i++)↵
{↵
if (i < n - m + 1)↵
rest.push_back(a[i]);↵
else↵
ans += a[i];↵
}↵
int k = len(rest);↵
ans += (rest[(k - 1) / 2] + rest[k / 2]) / 2.0;↵
cout << ans << '\n';↵
return 0;↵
}↵
↵
int32_t main()↵
{↵
ios_base::sync_with_stdio(0);↵
cin.tie(0);↵
int t = 1;↵
cin >> t;↵
cout << fixed << setprecision(12);↵
for (int _ = 1; _ <= t; _++)↵
{↵
cout << "Case #" << _ << ": ";↵
solve_case();↵
}↵
return 0;↵
}↵
~~~~~↵
↵
↵
</spoiler>↵
↵
