oj.uz

답안 #1029259

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1029259 2024-07-20T14:25:13 Z misteg168 Chase (CEOI17_chase) C++17
100 / 100
 261 ms 173908 KB 
#include <cstdio>
#include <cstring>
#include <cmath>
#include <vector>

#define maxn 100001
#define maxv 101

using namespace std;
typedef long long ll;

const ll MOD = 1000000007LL;

int n,v;
vector<int> graf[maxn];
ll p[maxn];
ll gain[maxn];
ll cont[maxn][maxv];
ll arrive[maxn][maxv];
pair<ll,ll> bcont[maxv][2];
pair<ll,ll> bprev[maxv][2];
ll best;

void dp(int nd, int pr){
	for(int i=0;i<graf[nd].size();i++)if(graf[nd][i]!=pr)dp(graf[nd][i],nd);
	for(int i=0;i<=v;i++)cont[nd][i]=0;
	for(int i=0;i<=v;i++)for(int j=0;j<2;j++)bcont[i][j]=make_pair(0,-1);
	for(int i=0;i<graf[nd].size();i++){
		if(pr==-1)break;
		int next=graf[nd][i];
		if(next==pr)continue;
		for(int j=0;j<=v;j++)cont[nd][j]=max(cont[nd][j],cont[next][j]);
		for(int j=1;j<=v;j++)cont[nd][j]=max(cont[nd][j],cont[next][j-1]+gain[nd]-p[pr]);
	}
	for(int i=0;i<graf[nd].size();i++){
		int next=graf[nd][i];
		if(next==pr)continue;
		for(int j=0;j<=v;j++){
			ll adv = cont[next][j];
			if(adv>=bcont[j][0].first){
				bcont[j][1]=bcont[j][0];
				bcont[j][0]=make_pair(adv,next);
				continue;
			}
			if(adv>bcont[j][1].first)bcont[j][1]=make_pair(adv,next);
		}
	}
	for(int i=0;i<=v;i++)arrive[nd][i]=i==0?0:gain[nd];
	for(int i=0;i<=v;i++)for(int j=0;j<2;j++)bprev[i][j]=make_pair(i==0?0:gain[nd],nd);
	for(int i=0;i<graf[nd].size();i++){
		int prev=graf[nd][i];
		if(prev==pr)continue;
		for(int j=0;j<=v;j++)arrive[nd][j]=max(arrive[nd][j],arrive[prev][j]);
		for(int j=1;j<=v;j++)arrive[nd][j]=max(arrive[nd][j],arrive[prev][j-1]+gain[nd]-p[prev]);
		for(int j=0;j<=v;j++){
			ll adv=arrive[prev][j];
			if(j>0)adv=max(adv,arrive[prev][j-1]+gain[nd]-p[prev]);
			if(adv>=bprev[j][0].first){
				bprev[j][1]=bprev[j][0];
				bprev[j][0]=make_pair(adv,prev);
			} else if(adv>bprev[j][1].first)bprev[j][1]=make_pair(adv,prev);
		}
	}
	for(int i=0;i<=v;i++){
		ll pgain = 0;
		if(bcont[i][0].second!=bprev[v-i][0].second)pgain=bcont[i][0].first+bprev[v-i][0].first;
		else pgain = max(bcont[i][0].first+bprev[v-i][1].first,bcont[i][1].first+bprev[v-i][0].first);
		best=max(best,pgain);
	}
}

int main(){
	scanf("%d%d",&n,&v);
	for(int i=1;i<=n;i++)scanf("%lld",p+i);
	memset(gain,0,sizeof(gain));
	for(int i=0;i<n-1;i++){
		int a,b;
		scanf("%d%d",&a,&b);
		graf[a].push_back(b);
		graf[b].push_back(a);
		gain[a]+=p[b];
		gain[b]+=p[a];
	}
	best=0;
	dp(1,-1);
	printf("%lld\n",best);
	return 0;
}

Compilation message

chase.cpp: In function 'void dp(int, int)':
chase.cpp:25:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |  for(int i=0;i<graf[nd].size();i++)if(graf[nd][i]!=pr)dp(graf[nd][i],nd);
      |              ~^~~~~~~~~~~~~~~~
chase.cpp:28:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |  for(int i=0;i<graf[nd].size();i++){
      |              ~^~~~~~~~~~~~~~~~
chase.cpp:35:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |  for(int i=0;i<graf[nd].size();i++){
      |              ~^~~~~~~~~~~~~~~~
chase.cpp:50:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 |  for(int i=0;i<graf[nd].size();i++){
      |              ~^~~~~~~~~~~~~~~~
chase.cpp: In function 'int main()':
chase.cpp:73:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   73 |  scanf("%d%d",&n,&v);
      |  ~~~~~^~~~~~~~~~~~~~
chase.cpp:74:28: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   74 |  for(int i=1;i<=n;i++)scanf("%lld",p+i);
      |                       ~~~~~^~~~~~~~~~~~
chase.cpp:78:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   78 |   scanf("%d%d",&a,&b);
      |   ~~~~~^~~~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 3420 KB Output is correct
2 Correct 1 ms 3420 KB Output is correct
3 Correct 2 ms 3420 KB Output is correct
4 Correct 1 ms 3420 KB Output is correct
5 Correct 1 ms 3420 KB Output is correct
6 Correct 1 ms 3420 KB Output is correct

Subtask #2
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 3420 KB Output is correct
2 Correct 1 ms 3420 KB Output is correct
3 Correct 2 ms 3420 KB Output is correct
4 Correct 1 ms 3420 KB Output is correct
5 Correct 1 ms 3420 KB Output is correct
6 Correct 1 ms 3420 KB Output is correct
7 Correct 3 ms 5212 KB Output is correct
8 Correct 2 ms 5212 KB Output is correct
9 Correct 2 ms 5212 KB Output is correct
10 Correct 3 ms 5000 KB Output is correct
11 Correct 2 ms 5212 KB Output is correct
12 Correct 2 ms 5212 KB Output is correct

Subtask #3
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 220 ms 173908 KB Output is correct
2 Correct 199 ms 173908 KB Output is correct
3 Correct 142 ms 167880 KB Output is correct
4 Correct 112 ms 167764 KB Output is correct
5 Correct 219 ms 167760 KB Output is correct
6 Correct 219 ms 167652 KB Output is correct
7 Correct 224 ms 167764 KB Output is correct

Subtask #4
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 3420 KB Output is correct
2 Correct 1 ms 3420 KB Output is correct
3 Correct 2 ms 3420 KB Output is correct
4 Correct 1 ms 3420 KB Output is correct
5 Correct 1 ms 3420 KB Output is correct
6 Correct 1 ms 3420 KB Output is correct
7 Correct 3 ms 5212 KB Output is correct
8 Correct 2 ms 5212 KB Output is correct
9 Correct 2 ms 5212 KB Output is correct
10 Correct 3 ms 5000 KB Output is correct
11 Correct 2 ms 5212 KB Output is correct
12 Correct 2 ms 5212 KB Output is correct
13 Correct 220 ms 173908 KB Output is correct
14 Correct 199 ms 173908 KB Output is correct
15 Correct 142 ms 167880 KB Output is correct
16 Correct 112 ms 167764 KB Output is correct
17 Correct 219 ms 167760 KB Output is correct
18 Correct 219 ms 167652 KB Output is correct
19 Correct 224 ms 167764 KB Output is correct
20 Correct 250 ms 167680 KB Output is correct
21 Correct 120 ms 167548 KB Output is correct
22 Correct 234 ms 167528 KB Output is correct
23 Correct 113 ms 167760 KB Output is correct
24 Correct 261 ms 167752 KB Output is correct
25 Correct 172 ms 167504 KB Output is correct
26 Correct 211 ms 173908 KB Output is correct
27 Correct 220 ms 173872 KB Output is correct