Submission #649942

#	Time	Username	Problem	Language	Result	Execution time	Memory
649942		KoalaMuch	Race (IOI11_race)	C++14	Compilation error	0 ms	0 KiB

race

#include "race.h"
#include<iostream>
#include<utility>
#include<vector>
#include<map>
#include <cstring>
using namespace std;
const long long N = 2e5+5;
long long sz[N];
long long st[N];
long long ft[N];
long long ver[N];
long long orig_len[N];
long long orig_sum[N];
map<long long,long long> mem;
vector<pair<long long,long long>> g[N];
long long t;
long long ans = 1e9;
bool vis[N];
void preprocess(long long u,long long len,long long sum,long long p){
    if(vis[u])  return;
    vis[u] = true;
    ++t;
    st[u] = t;
    ver[t] = u;
    orig_sum[u] = sum;
    orig_len[u] = len;
    sz[u] = 1;
    for(auto &x:g[u]){
        if(x.first!=p){
            preprocess(x.first,len+1,sum+x.second,u);
            sz[u]+=sz[x.first];
        }
    }
    ft[u] = t;
}
void solve(long long u,long long target,long long p,bool keep){
    if(vis[u])  return;
    vis[u] = true;
    long long mx = -1,big_child = -1,del_sum = orig_sum[u],del_len = orig_len[u];
    for(auto &x:g[u])   if(x.first!=p&&sz[x.first]>mx)  mx = sz[x.first],big_child = x.first;
    for(auto &x:g[u]){
        if(x.first!=p&&x.first!=big_child){
            solve(x.first,target,u,false);
        }
    }
    if(big_child!=-1){
        solve(big_child,target,u,true);
    }
    long long need = target-orig_sum[u]+2*del_sum;
    if(need>=0&&mem.find(need)!=mem.end())  ans = min(ans,mem[need]+orig_len[u]-2*del_len);
    if(mem.find(orig_sum[u])==mem.end())   mem[orig_sum[u]] = orig_len[u];
    mem[orig_sum[u]] = min(mem[orig_sum[u]],orig_len[u]);
    for(auto &x:g[u]){
        if(x.first!=p&&x.first!=big_child){
            for(long long i=st[x.first];i<=ft[x.first];i++){
                long long v = ver[i];
                need = target-orig_sum[v]+2*del_sum;
                if(need>=0&&mem.find(need)!=mem.end())  ans = min(ans,mem[need]+orig_len[v]-2*del_len);
            }
            for(long long i=st[x.first];i<=ft[x.first];i++){
                 long long v = ver[i];
                 if(mem.find(orig_sum[v])==mem.end())   mem[orig_sum[v]] = orig_len[v];
                 mem[orig_sum[v]] = min(mem[orig_sum[v]],orig_len[v]);
            }
        }
    }
    if(!keep){
        for(long long i=st[u];i<=ft[u];i++){
            if(mem.find(orig_sum[ver[i]])!=mem.end()) mem.erase(orig_sum[ver[i]]);
        }
    }
}
int best_path(int N, int K, int H[][2], int L[])
{
  for(long long i=0;i<N;i++)  g[H[i][0]].push_back({H[i][1],L[i]}),g[H[i][1]].push_back({H[i][0],L[i]});
  preprocess(0,0,0,0);
  memset(vis,false,sizeof vis);
  solve(0,K,0,true);
  if(ans>=N)  return -1;
  return ans;
}
int n, K;
int H[N][2];
int L[N];
void read_input()
{
  long long i;
  scanf("%d %d",&n,&K);
  for(i=0; i<n-1; i++)
    scanf("%d %d %d",&H[i][0],&H[i][1],&L[i]);
}
int main(){
    int ans;
    read_input();
    ans = best_path(n,K,H,L);
    //for(int i=0;i<n;i++)    cout << st[i] << " " << ft[i] << "\n";
    cout << ans << "\n";
    return 0;
}
/*
11 12
0 1 3
0 2 4
2 3 5
3 4 4
4 5 6
0 6 3
6 7 2
6 8 5
8 9 6
8 10 7

3 3
0 1 1
1 2 1
*/

Compilation message (stderr)

race.cpp: In function 'void read_input()':
race.cpp:89:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |   scanf("%d %d",&n,&K);
      |   ~~~~~^~~~~~~~~~~~~~~
race.cpp:91:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   91 |     scanf("%d %d %d",&H[i][0],&H[i][1],&L[i]);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/ccuCCgwk.o: in function `read_input()':
race.cpp:(.text+0x350): multiple definition of `read_input()'; /tmp/cc5BVnpk.o:grader.cpp:(.text+0x0): first defined here
/usr/bin/ld: /tmp/ccuCCgwk.o: in function `main':
race.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cc5BVnpk.o:grader.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status