Submission #67154

#TimeUsernameProblemLanguageResultExecution timeMemory
67154hamzqq9Balanced Tree (info1cup18_balancedtree)C++14
10 / 100
240 ms2024 KiB
#include<bits/stdc++.h> #define st first #define nd second #define pb push_back #define ppb pop_back #define umax(x,y) x=max(x,y) #define umin(x,y) x=min(x,y) #define ll long long #define ii pair<int,int> #define iii pair<int,ii> #define sz(x) ((int) x.size()) #define orta ((bas+son)>>1) #define all(x) x.begin(),x.end() #define dbgs(x) cerr<<(#x)<<" --> "<<(x)<<" " #define dbg(x) cerr<<(#x)<<" --> "<<(x)<<endl;getchar() #define pw(x) (1<<(x)) #define inf 2000000000 #define MOD 1000000007 #define N 1005 #define MAX 10000006 #define LOG 22 using namespace std; int n,x,y,T; int NE[N][2]; int ans,cev; int c[N],temp[N]; vector<int> v[N]; void S3() {} void NDFS(int node,int ata,int NEE[]) { /* printf("%d\n",node); for(int i=0;i<2;i++) printf("%d ",NEE[i]); printf("\n----------\n");*/ int NEN[2]; umax(ans,min(NEE[c[node]],NE[node][c[node]])); int mn[2][2]={NEE[0],inf,NEE[1],inf}; swap(mn[c[node]][0],mn[c[node]][1]); mn[c[node]][0]=0; for(int i:v[node]) { if(i==ata) continue ; for(int j=0;j<2;j++) { if(NE[i][j]+1<mn[j][1]) { mn[j][1]=NE[i][j]+1; if(mn[j][1]<mn[j][0]) swap(mn[j][1],mn[j][0]); } } if(1<mn[c[i]][1]) { mn[c[i]][1]=1; if(mn[c[i]][1]<mn[c[i]][0]) swap(mn[c[i]][1],mn[c[i]][0]); } } for(int i:v[node]) { if(i==ata) continue ; int t0=(c[i]==0?1:NE[i][0]+1); int t1=(c[i]==1?1:NE[i][1]+1); NEN[0]=(mn[0][0]==t0?mn[0][1]:mn[0][0])+1; NEN[1]=(mn[1][0]==t1?mn[1][1]:mn[1][0])+1; NDFS(i,node,NEN); } } void SDFS(int node,int ata) { NE[node][c[node]]=inf; NE[node][!c[node]]=inf; for(int i:v[node]) { if(i==ata) continue ; SDFS(i,node); umin(NE[node][0],NE[i][0]+1); if(c[i]==0) NE[node][0]=1; umin(NE[node][1],NE[i][1]+1); if(c[i]==1) NE[node][1]=1; } // printf("node-->%d ne0-->%d ne1-->%d\n",node,NE[node][0],NE[node][1]); } void back_track(int now) { if(now>n) { SDFS(1,0); int NE[2]; NE[0]=NE[1]=inf; ans=0; NDFS(1,0,NE); if(cev>ans) { cev=ans; for(int i=1;i<=n;i++) temp[i]=c[i]; } return ; } if(c[now]!=-1) back_track(now+1); else { c[now]=1; back_track(now+1); c[now]=0; back_track(now+1); c[now]=-1; } } void S2() { SDFS(1,0); int NE[2]; NE[0]=NE[1]=inf; ans=0; NDFS(1,0,NE); if(ans==inf) { printf("-1\n"); return ; } printf("%d\n",ans); for(int i=1;i<=n;i++) printf("%d ",c[i]); puts(""); } void S1() { cev=inf; back_track(1); if(cev==inf) { printf("-1\n"); return ; } printf("%d\n",cev); for(int i=1;i<=n;i++) printf("%d ",temp[i]); puts(""); } bool is_path() { int leaf=0; for(int i=1;i<=n;i++) { if(sz(v[i])>2) return false; if(sz(v[i])==1) leaf++; } return (n==1 || leaf==2); } void read() { scanf("%d",&n); for(int i=1;i<n;i++) { scanf("%d %d",&x,&y); v[x].pb(y); v[y].pb(x); } for(int i=1;i<=n;i++) scanf("%d",&c[i]); } void clear() { for(int i=1;i<=n;i++) v[i].clear(); } int main() { // freopen("input.txt","r",stdin); scanf("%d",&T); for(int t=1;t<=T;t++) { read(); if(T<=500 && n<=17) S1(); else if(is_path()) S3(); else S2(); clear(); } }

Compilation message (stderr)

balancedtree.cpp: In function 'void read()':
balancedtree.cpp:230:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
balancedtree.cpp:234:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d",&x,&y);
   ~~~~~^~~~~~~~~~~~~~~
balancedtree.cpp:241:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i=1;i<=n;i++) scanf("%d",&c[i]);
                        ~~~~~^~~~~~~~~~~~
balancedtree.cpp: In function 'int main()':
balancedtree.cpp:255:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&T);
  ~~~~~^~~~~~~~~
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