Submission #857791

#	Time	Username	Problem	Language	Result	Execution time	Memory
857791		caohung06	Putovanje (COCI20_putovanje)	C++17	110 / 110	103 ms	34640 KiB

putovanje

#include <bits/stdc++.h>
#define ll long long
#define f first
#define s second
using namespace std;
vector<pair<ll,ll>> g[100050];
ll p[100050][22],h[100050],n,u,v,c1[100050],c2[100050],dem[100050],d[100050],ans;
ll getbit(ll x,ll k)
{
    return (x>>k)&1;
}
void dfs(int u)
{
    for(int v=0; v<g[u].size(); v++)
    {
        if(g[u][v].f!=p[u][0])
        {
            h[g[u][v].f]=h[u]+1;
            p[g[u][v].f][0]=u;
            for(int i=1; i<=18; i++)
            {
                p[g[u][v].f][i]=p[p[g[u][v].f][i-1]][i-1];
            }
            dfs(g[u][v].f);
        }
    }
}
ll lca(int u,int v)
{
    if(h[u]<h[v]) swap(u,v);
    int delta=h[u]-h[v];
    for(int i=0; i<=18; i++)
    {
        if(getbit(delta,i)==1)
        {
            u=p[u][i];
        }
    }
    if(u==v) return u;
    for(int i=18; i>=0; i--)
    {
        if(p[u][i]!=p[v][i])
        {
            u=p[u][i];
            v=p[v][i];
        }
    }
    return p[u][0];
}

void dfs2(int u,int id)
{
    for(int v=0; v<g[u].size(); v++)
    {
        if(g[u][v].f!=p[u][0])
        {
            dfs2(g[u][v].f,g[u][v].s);
            d[u]+=d[g[u][v].f];
        }
    }
    dem[id]=d[u];
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    // freopen("friend.inp", "r", stdin);
    // freopen("friend.out", "w", stdout);
    cin>>n;
    for(int i=1; i<=n-1; i++)
    {
        cin>>u>>v>>c1[i]>>c2[i];
        g[u].push_back({v,i});
        g[v].push_back({u,i});
    }
    dfs(1);
    for(int i=1; i<=n-1; i++)
    {
        d[i]++;
        d[i+1]++;
        d[lca(i,i+1)]-=2;
    }
    dfs2(1,0);
    for(int i=1; i<=n; i++)
    {
        ans+=min(dem[i]*c1[i],c2[i]);
    }
    cout<<ans;
    return 0;
}

Compilation message (stderr)

putovanje.cpp: In function 'void dfs(int)':
putovanje.cpp:14:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 |     for(int v=0; v<g[u].size(); v++)
      |                  ~^~~~~~~~~~~~
putovanje.cpp: In function 'void dfs2(int, int)':
putovanje.cpp:53:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |     for(int v=0; v<g[u].size(); v++)
      |                  ~^~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 25 / 25
• Subtask 3: 65 / 65