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ID题目提交者结果用时内存语言文件大小提交时间测评时间
#172703#2065. Cyclic DistanceKLPP#TL 42ms11736kbC++202.3kb2023-09-09 20:15:592023-09-09 20:16:03

Judging History

你现在查看的是最新测评结果

  • [2023-09-09 20:16:03]
  • 评测
  • 测评结果:TL
  • 用时:42ms
  • 内存:11736kb
  • [2023-09-09 20:15:59]
  • 提交

answer

#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
using namespace std;
using namespace __gnu_pbds;
typedef long long int lld;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
#define rep(i,a,b) for(int i=a;i<b;i++)
#define trav(a,v) for(auto a:v)
vector<vector<pair<int,lld> > >nei;
lld dist[1000000];
bool vis[1000000];
int lab[1000000];
int n,k;
void DFS(int node, lld d=0, int label=-1){
	dist[node]=d;
	vis[node]=true;
	lab[node]=label;
	trav(a,nei[node]){
		if(!vis[a.first]){
			if(label==-1)DFS(a.first,d+a.second,a.first);
			else DFS(a.first,d+a.second,label);
		}
	}
}
void st(int node){
	rep(i,0,n)vis[i]=false;
	DFS(node);
}
void reset(){
	rep(i,0,n)vis[i]=false;
}
int sz[1000000];
bool bl[1000000];
void getsz(int node){
	vis[node]=true;
	sz[node]=1;
	trav(a,nei[node]){
		if(!vis[a.first] && !bl[a.first]){
			getsz(a.first);
			sz[node]+=sz[a.first];
		}
	}
}
int getcent(int node, int treesz){
	trav(a,nei[node]){
		if(!bl[a.first] && sz[node]>sz[a.first] && sz[a.first]*2>treesz){
			return getcent(a.first,treesz);
		}
	}
	return node;
}
int cnt[1000000];
vector<pair<lld,int> >V;
int exc;
lld test(int node){
	exc=-1;
	st(node);
	V.clear();
	rep(i,0,n)cnt[i]=0;
	rep(i,0,n){
		V.push_back({-dist[i],lab[i]});
	}
	sort(V.begin(),V.end());
	int tot=0;
	lld ans=0;
	trav(a,V){
		if(tot==k)continue;
		lld D=-a.first;
		int v=a.second;
		if(2*(cnt[v]+1)<=k){
			cnt[v]++;
			tot++;
			ans+=2*D;
		}else{
			exc=v;
		}
	}
	return ans;
}
void solve(){
	cin>>n>>k;
	nei.clear();
	nei.resize(n);
	rep(i,0,n)vis[i]=false,bl[i]=false;
	rep(i,0,n-1){
		int x,y;
		lld c;
		cin>>x>>y>>c;
		x--;y--;
		nei[x].push_back({y,c});
		nei[y].push_back({x,c});
	}
	lld ans=0;
	int ver=0;
	while(true){
		reset();
		getsz(ver);
		int S=sz[ver];
		if(S<=2)break;
		int cen=getcent(ver,S);
		ans=max(ans,test(cen));
		if(exc==-1){
			cout<<ans<<"\n";
			return;
		}
		bl[cen]=true;
		ver=exc;
	}
	vector<int> V;
	rep(i,0,n){
		if(vis[i]){
			V.push_back(i);
		}
	}
	trav(a,V)ans=max(ans,test(a));
	cout<<ans<<"\n";
}

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	int tt=1;
	cin>>tt;
	while(tt--){
		solve();
	}
}

详细

Test #1:

score: 100
Accepted
time: 0ms
memory: 11728kb

input:

1
5 3
1 2 4
1 3 1
1 4 8
4 5 9

output:

44

result:

ok single line: '44'

Test #2:

score: 0
Accepted
time: 42ms
memory: 11736kb

input:

57206
3 2
1 2 574927
2 3 406566
2 2
1 2 308806
4 3
1 2 312588
2 3 500141
2 4 53602
3 3
1 2 797183
2 3 944061
5 3
1 2 624010
2 3 488613
3 4 734514
4 5 497493
5 4
1 2 540278
2 3 488655
2 4 228989
2 5 653896
2 2
1 2 569117
4 2
1 2 821764
2 3 499471
1 4 549060
2 2
1 2 991159
2 2
1 2 482941
5 4
1 2 30462...

output:

1962986
617612
1732662
3482488
4689260
3823636
1138234
3740590
1982318
965882
3418504
5026562
1623414
1885106
1952142
3050630
1691896
3102076
2380932
3076270
5697196
7258020
879020
2500212
3613854
1358950
1182198
2273662
2331560
1681964
8917452
2373066
3163042
3104226
3642898
3162310
5058442
3669186...

result:

ok 57206 lines

Test #3:

score: 0
Accepted
time: 34ms
memory: 9644kb

input:

57087
3 3
1 2 34132
1 3 188096
2 2
1 2 996527
2 2
1 2 475736
5 3
1 2 329834
2 3 339687
1 4 954113
4 5 224354
2 2
1 2 641444
2 2
1 2 114059
5 3
1 2 635722
1 3 552627
1 4 721758
3 5 396156
4 3
1 2 655099
2 3 963393
1 4 953969
5 2
1 2 369719
1 3 22087
1 4 531252
3 5 449025
4 3
1 2 788498
1 3 220292
1 4...

output:

444456
1993054
951472
3695976
1282888
228118
4612526
5144922
2004728
3309502
2626844
3053048
3939444
3790784
2617770
38866
3033250
5707738
511666
403846
1923106
3331606
3447180
2329518
5656124
33582
2283312
3454982
110590
3125394
4517486
4522330
2352316
3966810
3463746
5181112
3089346
1260326
466418...

result:

ok 57087 lines

Test #4:

score: -100
Time Limit Exceeded

input:

33344
9 6
1 2 562996
1 3 312637
3 4 591016
1 5 811983
2 6 896220
3 7 854379
2 8 861166
1 9 672337
8 6
1 2 53530
1 3 712638
1 4 539356
1 5 179377
3 6 456495
2 7 730760
4 8 934379
3 3
1 2 87024
1 3 328551
3 3
1 2 664600
1 3 519786
5 4
1 2 374521
1 3 484148
2 4 501378
1 5 280691
10 3
1 2 676949
1 3 639...

output:


result: