Submission #14669

#TimeUsernameProblemLanguageResultExecution timeMemory
14669minsuRace (IOI11_race)C++14
21 / 100
3069 ms13764 KiB
#include <bits/stdc++.h> #define SZ(X) ((int)(X).size()) #define ALL(X) (X).begin(), (X).end() #define REP(I, N) for (int I = 0; I < (N); ++I) #define REPP(I, A, B) for (int I = (A); I < (B); ++I) #define RREP(I, N) for (int I= (N)-1; I>=0; --I) #define RREPP(I, A, B) for(int I = (B)-1; I>=A; --I) #define CASET int ___T, case_n = 1; scanf("%d ", &___T); while (___T-- > 0) #define MP make_pair #define PB push_back #define MS0(X) memset((X), 0, sizeof((X))) #define MS1(X) memset((X), -1, sizeof((X))) #define LEN(X) strlen(X) #define F first #define S second #define debug(A) REP(i, A.size()) cerr << A[i] << ' '; cerr << '\n' using namespace std; typedef pair<int, int> ii; typedef vector<int> vi; typedef vector<vi> vvi; typedef vector<ii> vii; typedef long long lld; typedef unsigned long long ulld; typedef pair<lld, lld> plld; typedef vector<lld> vlld; typedef vector<vlld> vvlld; typedef long double ld; typedef vector<ld> vld; typedef vector<vld> vvld; const int MAXN=5e5+10; const int MAXK=1e6+10; const int INF=987654321; struct Edge{ int to, co; }; typedef vector< vector<Edge> > vve; vve linked; vi deleted; int n, k, A[MAXK], size[MAXN], par[MAXN]; int solve(int root){ struct Sres{ int now, nowk, len, iter, par; }; int ret=INF; MS0(A); for(auto it : linked[root]){ if( deleted[it.to] ) continue; vii paths; stack<Sres> st; st.push({it.to, it.co, 1, 0, root}); while(!st.empty()){ Sres& here=st.top(); if(SZ(linked[here.now]) == here.iter) { paths.PB( {here.nowk, here.len} ); st.pop(); continue; } Edge there=linked[here.now][here.iter]; here.iter++; if( there.to==here.par || deleted[there.to] ) { continue; } if( here.nowk + there.co <= k ) st.push({there.to, here.nowk + there.co, here.len+1, 0, here.now}); } for(auto it : paths) if(A[k-it.F]) ret=min(ret, A[k-it.F]+it.S); for(auto it : paths) A[it.F]=min( ( A[it.F]==0 ? INF : A[it.F] ), it.S); } if(A[k]) ret=min(ret, A[k]); return ret; } int dnc(int root){ struct Sres{ int now, iter; }; vi vs; stack<Sres> st; st.push({root, 0}); par[root]=-1; size[root]=1; while(!st.empty()){ Sres& here=st.top(); if(SZ(linked[here.now])==here.iter){ vs.PB(here.now); if(par[here.now]!=-1) size[par[here.now]]+=size[here.now]; st.pop(); continue; } Edge there=linked[here.now][here.iter]; here.iter++; if(deleted[there.to] || there.to==par[here.now]) { continue; } par[there.to]=here.now; st.push({there.to, 0}); size[there.to]=1; } int sn=SZ(vs), nroot=-1; if(sn==1) return INF; for(auto it : vs){ int maxi=0; for(auto there : linked[it]){ if(deleted[there.to]) continue; if(par[it] == there.to) maxi=max(maxi, sn-size[it]); else maxi=max(maxi, size[there.to]); } if(maxi<=sn/2) { nroot=it; break; } } assert(nroot!=-1); int ret=solve(nroot); deleted[nroot]=1; for(auto it : linked[nroot]){ if(deleted[it.to]) continue; ret=min(ret, dnc(it.to)); } return ret; } int best_path(int N, int K, int H[][2], int L[]){ vve(N).swap(linked); vi(N, 0).swap(deleted); for(int i=0;i<N-1;i++){ linked[H[i][0]].PB({H[i][1], L[i]}); linked[H[i][1]].PB({H[i][0], L[i]}); } n=N, k=K; int ret=dnc(0); return ( ret==INF )? -1 : ret; }
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