# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
936873 | william950615 | 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 F first
#define S second
#define mkp make_pair
#define PH push
#define PB push_back
#define REP(i,N) for( int i = 0; i < (N); ++i )
#define FOR(i,a,b) for( int i = (a); i <= (b); ++i )
#define ALL(x) begin(x), end(x)
#define MEM(x) memset(x, 0, sizeof(x))
typedef long long ll;
typedef pair<int,int> pii;
template<typename T>
using V=vector<T>;
void solve() {
int N, K; cin >> N >> K;
V<pii> vc(N+1);
const int INF = 1e9;
FOR(i,1,N) cin >> vc[i].F >> vc[i].S;
for( auto &i : vc ) if( i.S == -1 ) i.S = INF;
sort( vc.begin()+1, vc.end(), [&]( auto&a, auto&b) {
return a.S < b.S;
});
double dp[ N+1 ][ K+1 ][ K+1 ];
auto init = [&]() {
for( auto &i : dp ) for( auto &j : i ) for( auto &k : j )
k = INF;
dp[ 0 ][ 1 ][ 0 ] = 0;
};
double ans=INF;
for( int p = 1; p <= K; ++p ) {
init();
for( int i = 1; i <= N; ++i ) {
for( int j = 1; j <= K; ++j ) {
for( int k = 1; k <= K; ++k ) {
dp[ i ][ j ][ k ] = min({
dp[i-1][j-1][k-1]+(1.0*vc[i].S/(j-1)),
dp[i-1][j][k-1] + (1.0*vc[i].F/p),
dp[i-1][j][k]
});
}
}
}
//fprintf(stderr, "ans:(%.16lf), p(%d)\n", ans, p );
ans = min( dp[N][p][K], ans );
}
cout << fixed << setprecision(10);
cout << ans << '\n';
}
int main() {
int T = 1;
#ifdef LOCAL
freopen( "input.txt", "r", stdin);
freopen( "output.txt", "w", stdout );
cin >> T;
#else
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#endif
while(T--) solve();
}