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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
#217654#5102. Dungeon CrawlerqzezWA 3ms11856kbC++142.5kb2023-10-17 08:12:132023-10-17 08:12:13

Judging History

你现在查看的是最新测评结果

  • [2023-10-17 08:12:13]
  • 评测
  • 测评结果:WA
  • 用时:3ms
  • 内存:11856kb
  • [2023-10-17 08:12:13]
  • 提交

answer

#include<bits/stdc++.h>
using namespace std;
using ll=long long;
template<typename T>
ostream& operator << (ostream &out,const vector<T>&x){
	if(x.empty())return out<<"[]";
	out<<'['<<x[0];
	for(int len=x.size(),i=1;i<len;i++)out<<','<<x[i];
	return out<<']';
}
template<typename T>
ostream& operator << (ostream &out,const pair<T,T> &x){
	return out<<'('<<x.first<<','<<x.second<<')';
}
template<typename T>
vector<T> ary(const T *a,int l,int r){
	return vector<T>{a+l,a+1+r};
}
template<typename T>
void debug(T x){
	cerr<<x<<'\n';
}
template<typename T,typename ...S>
void debug(T x,S ...y){
	cerr<<x<<' ',debug(y...);
}
const int N=2e3+10;
int n,m;
vector<pair<int,int> >to[N];
struct Path{
	int fa[N],top[N],siz[N],son[N],dep[N];
	ll dis[N],f[N],g[N];
	#define v e.first
	#define w e.second
	void dfs1(int u){
		dep[u]=dep[fa[u]]+1,siz[u]=1;
		f[u]=dis[u];
		for(auto e:to[u])if(v^fa[u]){
			fa[v]=u,dis[v]=dis[u]+w,dfs1(v);
			siz[u]+=siz[v];
			if(siz[v]>siz[son[u]])son[u]=v;
			f[u]=max(f[u],f[v]);
		}
	}
	int dft,dfn[N],pos[N];
	void dfs2(int u,int t){
		top[u]=t,pos[dfn[u]=++dft]=u;
		if(son[u])dfs2(son[u],t);
		for(auto e:to[u])if(v^fa[u]&&v^son[u])dfs2(v,v);
	}
	void dfs3(int u){
		ll fi=g[u],se=fi;
		for(auto e:to[u])if(v^fa[u]){
			if(f[v]>fi)se=fi,fi=f[v];
			else se=max(se,f[v]);
		}
		// if(u==1&&!fa[2])debug(fi,se,to[u],fa[u],f[11]);
		for(auto e:to[u])if(v^fa[u]){
			g[v]=f[v]==fi?se:fi;
			dfs3(v);
		}
	}
	#undef v
	#undef w
	void init(int rt){
		dfs1(rt),dfs2(rt,rt),dfs3(rt);
	}
	int LCA(int u,int v){
		for(;top[u]^top[v];u=fa[top[u]]){
			if(dep[top[u]]<dep[top[v]])swap(u,v);
		}
		return dep[u]<dep[v]?u:v;
	}
	int jump(int u,int k){
		for(;k>dep[u]-dep[top[u]];u=fa[top[u]]){
			k-=dep[u]-dep[top[u]]+1;
		}
		return pos[dfn[u]-k];
	}
}T[N];
int main(){
	scanf("%d%d",&n,&m);
	ll sum=0;
	for(int i=1,u,v,w;i<n;i++){
		scanf("%d%d%d",&u,&v,&w);
		to[u].push_back({v,w}),to[v].push_back({u,w});
		sum+=w*2;
	}
	for(int i=1;i<=n;i++)T[i].init(i);
	// debug(sum);
	for(int rt,u,v;m--;){
		scanf("%d%d%d",&rt,&u,&v);
		int t=T[rt].LCA(u,v);
		if(v==t){
			puts("impossible");
		}else if(u==t){
			printf("%lld\n",sum-T[rt].f[rt]);
		}else{
			int x=T[rt].jump(u,T[rt].dep[u]-T[rt].dep[t]-1),y=T[rt].fa[t];
			// debug(x,T[rt].g[x],T[rt].f[11]);
			printf("%lld\n",min({
				sum-T[rt].g[x],
				sum-T[u].g[y]+T[u].dis[t]*2-T[rt].dis[t],
				sum+T[rt].dis[u]-T[u].f[u]
			}));
		}
	}
	return 0;
}

详细

Test #1:

score: 100
Accepted
time: 1ms
memory: 6512kb

input:

22 5
1 2 7
2 3 5
3 4 8
3 6 6
3 7 3
2 5 6
5 8 2
8 9 11
2 10 16
1 11 12
11 12 4
11 13 9
1 14 25
14 15 4
15 16 5
15 17 6
15 18 1
15 19 8
14 20 7
20 21 9
20 22 17
1 19 9
1 9 19
1 8 9
1 9 8
2 22 11

output:

316
293
293
impossible
314

result:

ok 5 lines

Test #2:

score: -100
Wrong Answer
time: 3ms
memory: 11856kb

input:

100 100
1 2 289384
2 3 930887
2 4 692778
4 5 636916
4 6 747794
4 7 238336
4 8 885387
8 9 760493
8 10 516650
8 11 641422
8 12 202363
8 13 490028
8 14 368691
8 15 520060
8 16 897764
16 17 513927
16 18 180541
16 19 383427
16 20 89173
16 21 455737
16 22 5212
16 23 595369
16 24 702568
16 25 956430
16 26 ...

output:

103526917
103484292
106288816
104379596
104405611
104775512
106037785
105291604
103838430
106026228
105396939
104175650
105894571
104509242
103971939
105376499
105223283
104153426
105082245
105932330
104130613
104800548
106846555
104138329
103769253
106879186
104044745
104385328
106973740
105460460
...

result:

wrong answer 7th lines differ - expected: '105434682', found: '106037785'