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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#60022 | #4809. Maximum Range | xiaoyaowudi | WA | 70ms | 33416kb | C++17 | 5.8kb | 2022-11-02 18:33:18 | 2022-11-02 18:33:21 |
Judging History
answer
#include <iostream>
#include <vector>
#include <tuple>
#include <algorithm>
#include <functional>
constexpr int N(100010),inf(1.01e9);
using t3i=std::tuple<int,int,int,int>;
using veci=std::vector<int>;
int bcnt,n,m;
t3i mxm[N],mnm[N];
veci pts[N],ts[N<<1],gs[N];
#define DEBUG std::cerr<<__FUNCTION__<<std::endl
std::vector<std::pair<int,int>> eds[N],es[N];
void tarjan(int u)
{
static std::tuple<int,int,int> stk[N];
static int top,dfn[N],low[N],dcnt;
dfn[u]=low[u]=++dcnt;stk[++top]={u,-1,-1};
for(auto [v,w]:es[u])
{
if(!dfn[v])
{
tarjan(v);low[u]=std::min(low[u],low[v]);
if(low[v]==dfn[u])
{
int k=++bcnt;
pts[k].emplace_back(u);
mxm[k]={-inf,0,0,0},mnm[k]={inf,0,0,0};
while(1)
{
auto [x,y,w]=stk[top--];
// std::cerr<<x<<" "<<y<<" "<<w<<std::endl;
if(~y) eds[k].emplace_back(x,y),mxm[k]=std::max(mxm[k],{w,x,y,k+n}),mnm[k]=std::min(mnm[k],{w,x,y,k+n});
else
{
pts[k].emplace_back(x);
if(x==v) break;
}
}
if(eds[k].size()>1)
{
for(int v:pts[k]) ts[k+n].emplace_back(v),ts[v].emplace_back(k+n);
}
}
}
else if(dfn[v]<dfn[u]) stk[++top]={u,v,w},low[u]=std::min(low[u],dfn[v]);
}
}
std::pair<veci,veci> calc(const veci &vs,const veci &vall)
{
// DEBUG;
int l=vs.size(),u=vs[0],v=vs[l-1];
static int fu[N],fv[N];
static bool mk[N];
for(int k:vs) mk[k]=true;
std::function<void(int,int,int*)> dfs=[&dfs](int u,int fa,int *ff){ff[u]=fa;if(mk[u]) return;for(int v:gs[u]) if(!ff[v]) dfs(v,u,ff);};
fu[u]=-1;for(int k:gs[u]) if(!mk[k] && !fu[k]) dfs(k,u,fu);
fv[v]=-1;for(int k:gs[v]) if(!mk[k] && !fv[k]) dfs(k,v,fv);
// std::cerr<<"❤"<<std::endl;
if(fv[u])
{
// std::cerr<<"❤gyc"<<std::endl;
veci res;
for(int i(u);~i;i=fv[i]) res.emplace_back(i);
// std::cerr<<"end"<<std::endl;
return {vs,res};
}
int p1(1);while(!fv[vs[p1]]) ++p1;
int p2(p1+1);while(!fu[vs[p2]]) ++p2;
veci r1;for(int i(vs[p2]);~i;i=fu[i]) r1.emplace_back(i);std::reverse(r1.begin(),r1.end());r1.insert(r1.begin(),vs.begin()+p2+1,vs.end());
veci r2;r2.insert(r2.begin(),vs.begin(),vs.begin()+p1);for(int i(vs[p1]);~i;i=fv[i]) r2.emplace_back(i);
return {r1,r2};
}
veci solve_path(veci pts,int u,int v,int frb,int pre)
{
// DEBUG;
static int fs[N];
static bool vis[N];
fs[pre]=0;
std::function<void(int,int)> dfs=[&](int u,int fa)->void{fs[u]=fa;vis[u]=true;for(int v:gs[u]) if(!vis[v] && v!=frb) dfs(v,u);};
dfs(v,pre);
veci ret;
for(int k:pts) vis[k]=false;
for(int i(u);i;i=fs[i]) ret.emplace_back(i);
return ret;
}
std::pair<veci,veci> solve1(int idx,int u,int v,int s)
{
// DEBUG;
idx-=n;
for(auto [u,v]:eds[idx]) gs[u].emplace_back(v),gs[v].emplace_back(u);
std::pair<veci,veci> res;
if(u==s)
{
res=calc({s,v},pts[idx]);
}
else
{
res=calc(solve_path(pts[idx],s,v,u,u),pts[idx]);
}
for(int u:pts[idx]) gs[u].clear();
return res;
}
std::pair<veci,veci> solve2(int idx,int u,int v)
{
// DEBUG;
idx-=n;
for(auto [u,v]:eds[idx]) gs[u].emplace_back(v),gs[v].emplace_back(u);
auto res=calc(solve_path(pts[idx],u,v,0,0),pts[idx]);
for(int u:pts[idx]) gs[u].clear();
return res;
}
veci solve3(int idx,int u,int v,int s,int t)
{
// DEBUG;
idx-=n;
for(auto [u,v]:eds[idx]) gs[u].emplace_back(v),gs[v].emplace_back(u);
auto hp=[](std::pair<veci,veci> pr,veci vall)->veci
{
auto [p1,p2]=pr;
std::reverse(p2.begin(),p2.end());
p1.pop_back();p2.pop_back();
p1.insert(p1.end(),p2.begin(),p2.end());
for(int v:vall) gs[v].clear();
return p1;
};
if(v==s || v==t) return hp(calc({u,v,(s^t^v)},pts[idx]),pts[idx]);
else if(u==s || u==t) return hp(calc({v,u,(s^t^u)},pts[idx]),pts[idx]);
auto pt=solve_path(pts[idx],v,s,t,t);
int hu=-1,len=pt.size();
for(int k(0);k<len;++k) if(pt[k]==u){hu=k;break;}
if(~hu)
{
pt.erase(pt.begin()+1,pt.begin()+hu);
}
else pt.insert(pt.begin(),u);
return hp(calc(pt,pts[idx]),pts[idx]);
}
int main()
{
// DEBUG;
std::ios::sync_with_stdio(false);
std::cin.tie(0);std::cin>>n>>m;
for(int i(1),u,v,w;i<=m;++i) std::cin>>u>>v>>w,es[u].emplace_back(v,w),es[v].emplace_back(u,w);
tarjan(1);
static bool vis[N<<1];
std::function<void(int,t3i&,t3i&)> dfs1=[&dfs1](int u,t3i &mx,t3i &mn)->void
{
if(u>n) mx=std::max(mxm[u-n],mx),mn=std::min(mnm[u-n],mn);vis[u]=true;
for(int v:ts[u]) if(!vis[v]) dfs1(v,mx,mn);
};
int ans=-1,su,sv,sk,tu,tv,tk;
for(int i(1);i<=n;++i) if(!vis[i] && ts[i].size())
{
t3i mn{inf,0,0,0},mx{-inf,0,0,0};
dfs1(i,mx,mn);
auto [w1,e1u,e1v,v1]=mn;auto [w2,e2u,e2v,v2]=mx;
if(w2-w1>ans)
{
ans=w2-w1;
su=e1u;sv=e1v;sk=v1;
tu=e2u;tv=e2v;tk=v2;
}
}
std::cout<<ans<<std::endl;
if(sk!=tk)
{
static int ff[N<<1];
std::function<void(int,int)> dfs2=[&dfs2](int u,int fa)->void{ff[u]=fa;for(int v:ts[u])if(fa!=v) dfs2(v,u);};
dfs2(tk,0);
static int vs[N<<1],vc;
for(int i(tk);i;i=ff[i]) vs[++vc]=i;
auto [r1,r2]=solve1(sk,su,sv,vs[2]);
for(int i=3;i<vc;i+=2)
{
auto [c1,c2]=solve2(vs[i],vs[i-1],vs[i+1]);
c1.erase(c1.begin());c2.erase(c2.begin());
r1.insert(r1.end(),c1.begin(),c1.end());
r2.insert(r2.end(),c2.begin(),c2.end());
}
auto [c1,c2]=solve1(tk,tu,tv,vs[vc-1]);
std::reverse(c1.begin(),c1.end());std::reverse(c2.begin(),c2.end());
c1.erase(c1.begin());c2.erase(c2.begin());
r1.insert(r1.end(),c1.begin(),c1.end());
r2.insert(r2.end(),c2.begin(),c2.end());
std::reverse(r2.begin(),r2.end());r1.erase(r1.end());r2.erase(r2.end());
r1.insert(r1.end(),r2.begin(),r2.end());
std::cout<<r1.size()<<std::endl;
for(int v: r1) std::cout<<v<<" ";std::cout<<std::endl;
}
else
{
auto r1=solve3(sk,su,sv,tu,tv);
std::cout<<r1.size()<<std::endl;
for(int v:r1) std::cout<<v<<" ";std::cout<<std::endl;
}
return 0;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 0ms
memory: 22156kb
input:
5 7 1 2 1 1 3 -2 2 3 1 3 4 3 4 5 1 1 5 -1 2 5 2
output:
5 5 1 3 4 5 2
result:
ok ok
Test #2:
score: -100
Wrong Answer
time: 70ms
memory: 33416kb
input:
99997 100000 12238 99016 352755196 99016 25485 -412473602 25485 2440 991507552 2440 31171 -181894654 36970 2440 -800167579 2440 41865 -148191946 96629 31171 847888506 36970 95740 395546542 27992 2440 647886610 99016 29557 369124914 80795 27992 -673871966 36970 3509 573208857 57672 29557 874406776 41...
output:
1959330954 56 4697 96048 94991 31171 2440 27992 90367 94522 24616 56899 57732 80256 964 80875 37318 41262 21467 79804 22393 7822 43423 93639 10503 73944 25485 99016 29557 57672 69259 68883 94991 86274 74677 92617 86665 76022 72089 22074 96230 87712 51491 72825 3463 84407 67966 89628 84997 54073 6852...
result:
wrong answer Edge 94991-31171 does not appear in original graph