Submission #638728

#	Time	Username	Problem	Language	Result	Execution time	Memory
638728		jamezzz	Let's Win the Election (JOI22_ho_t3)	C++17	100 / 100	513 ms	332 KiB

Main

#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define sf scanf
#define pf printf
typedef long long ll;
typedef long double ld;
typedef pair<int,int> ii;
 
#define maxn 505
#define INF 1023456789
 
int n,k,a[maxn],b[maxn];
vector<ii> v;
ld memo[maxn];
 
int main(){
	sf("%d%d",&n,&k);
	for(int i=0;i<n;++i){
		int x,y;
		sf("%d%d",&x,&y);
		if(y==-1)y=INF;
		v.push_back({y,x});
	}
	sort(v.begin(),v.end());
	int cnt=0;
	for(int i=0;i<n;++i){
		tie(b[i],a[i])=v[i];
		if(b[i]!=INF)++cnt;
	}
	ld ans=INF;
	for(int take=0;take<=min(k,cnt);++take){
		for(int i=0;i<=n+1;++i){
			memo[i]=INF;
		}
		memo[0]=0;
		for(int pos=0;pos<n;++pos){
			for(int vote=k-take;vote>=0;--vote){
				ld ans=INF;
				//case 1: take this
				if(vote!=0)ans=min(ans,memo[vote-1]+(ld)a[pos]/(take+1));
				//case 2: don't take this
				//if this is one of the collaborators, add cost
				if(pos-vote<take){
					ans=min(ans,memo[vote]+(ld)b[pos]/(pos-vote+1));
				}
				else ans=min(ans,memo[vote]);
				memo[vote]=ans;
			}
		}
		ans=min(ans,memo[k-take]);
	}
	pf("%.15Lf\n",ans);
}

/*
7
5
393 646
375 666
374 676
320 635
288 668
284 758
333 702

1258.500000000000000
*/

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:20:4: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |  sf("%d%d",&n,&k);
      |    ^
Main.cpp:23:5: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   23 |   sf("%d%d",&x,&y);
      |     ^

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 11 / 11
• Subtask 4: 12 / 12
• Subtask 5: 33 / 33
• Subtask 6: 11 / 11
• Subtask 7: 23 / 23