| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 871860 | HorizonWest | Let's Win the Election (JOI22_ho_t3) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define db double
#define ll __int128
#define int long long
#define pb push_back
#define fs first
#define sd second
#define Mod long(1e9 + 7)
#define all(x) x.begin(), x.end()
#define unvisited long(-1)
#define Eps double(1e-9)
#define _for(i, n) for(int i = 0; i < (n); i++)
#define dbg(x) cout << #x ": " << x << endl;
const int Max = 1e6 + 7, Inf = 1e9 + 7;
void print(bool x) { cout << (x ? "YES" : "NO") << endl; }
string tostring (__int128 x)
{
string ans = "";
while(x > 0)
{
ans += (x % 10 + '0');
x /= 10;
}
reverse(all(ans));
return ans;
}
void printdb(double ans, int k)
{
cout << setiosflags(ios::fixed)
<< setiosflags(ios::showpoint)
<< setprecision(k) << ans << endl;
}
pair <db, db> fmin(pair<db, db> a, pair <db, db> b, db j)
{
if(db(a.fs + a.sd / j) < db(b.fs + b.sd / j))
return a;
else
return b;
}
int prec(vector <pair<db, db>> a, vector <pair<db, db>> b, int n, int m)
{
vector <db> take(n, 1);
for(db i = 1; i <= m; i++)
{
db Z1 = 0.0, Z2 = b[i-1].fs / i; int cnt = i - 1; //cerr << b[i-1].fs << endl;
for(int j = 0; j < n; j++)
{
//cerr << a[j].fs << " ";
if(cnt == m) break;
Z1 += take[a[j].sd] * a[j].fs / i;
cnt += take[a[j].sd];
}
cnt = i; take[b[i-1].sd] = 0;
for(int j = 0; j < n; j++)
{
if(cnt == m) break;
Z2 += take[a[j].sd] * a[j].fs / (i + 1);
cnt += take[a[j].sd];
}
//cerr << Z1 << " " << Z2 << endl;
if(Z1 <= Z2) return i;
}
return m;
}
void solve()
{
int n, m; cin >> n >> m;
vector <pair<db, db>> v(n), a(n), b(n);
for(int i = 0; i < n; i++)
{
cin >> v[i].sd >> v[i].fs;
if(v[i].fs == -1) v[i].fs = Inf;
a[i].fs = v[i].sd; b[i].fs = v[i].fs;
a[i].sd = b[i].sd = i;
}
sort(all(v)); sort(all(a)); sort(all(b));
db ans = Inf; int fx = prec(a, b, n, m);
//cerr << fx << endl;
for(db l = max(1, fx-5); l <= min(fx+5, m); l++)
{
vector <vector<vector<db>>> dp(n + 2, vector <vector<db>> (
m + 2, vector <db> (m + 2, Inf)
)); dp[0][1][0] = 0.000;
for(db i = 0; i < n; i++)
{
for(db j = 1; j <= l; j++)
{
for(db k = 0; k <= m; k++)
{
dp[i+1][j][k] = min(dp[i+1][j][k], dp[i][j][k]);
dp[i+1][j][k+1] = min(dp[i+1][j][k+1], dp[i][j][k] + v[i].sd / l);
if(v[i].fs != Inf)
{
dp[i+1][j+1][k+1] = min(dp[i+1][j+1][k+1], dp[i][j][k] + v[i].fs / j);
}
}
}
ans = min(ans, dp[i+1][l][m]);
}
}
printdb(ans, 5);
}
int32_t main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
int Q = 1; //cin >> Q;
while (Q--)
{
solve();
}
return 0;
}