Submission #817780

#	Time	Username	Problem	Language	Result	Execution time	Memory
817780		oneloveforever	Designated Cities (JOI19_designated_cities)	C++14	7 / 100	185 ms	35012 KiB

designated_cities

#include<bits/stdc++.h>
using namespace std;
#define ll long long
ll n,q;
struct edge
{
    ll x,value_x,value_y;
    edge(ll _x=0,ll _value_x=0,ll _value_y=0)
    {
        x=_x,value_x=_value_x,value_y=_value_y;
    }
};
vector<vector<edge> >a;
struct SUB1
{
    ll n;
    vector<ll>num_child,num_par;
    SUB1(ll _n=0)
    {
        n=_n;
        num_child.resize(n+7);
        num_par.resize(n+7);
    }
    void dfs_down(ll x,ll par)
    {
        for(edge need:a[x])
        {
            ll node=need.x;
            ll value_x=need.value_x;
            ll value_y=need.value_y;
            if(node==par)continue;
            dfs_down(node,x);
            num_child[x]+=num_child[node]+value_x;
        }
    }
    void dfs_up(ll x,ll par)
    {
        for(edge need:a[x])
        {
            ll node=need.x;
            ll value_x=need.value_x;
            ll value_y=need.value_y;
            if(node==par)continue;
            ll value=num_child[x]-num_child[node];
            value+=num_par[x]+value_y-value_x;
            num_par[node]=value;
            dfs_up(node,x);
        }
    }
    void calc()
    {
        dfs_down(1,0);
        dfs_up(1,0);
        ll ans=num_child[1];
        for(ll i=2;i<=n;i++)ans=min(ans,num_par[i]+num_child[i]);
        //for(ll i=1;i<=n;i++)cout<<num_par[i]<<" "<<num_child[i]<<endl;
        cout<<ans;
    }
};
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    ll n;
    cin>>n;
    a.resize(n+7);
    for(ll i=1;i<=n-1;i++)
    {
        ll x,y,value_x,value_y;
        cin>>x>>y>>value_x>>value_y;
        a[x].push_back({y,value_x,value_y});
        a[y].push_back({x,value_y,value_x});
    }
    ll q;
    cin>>q;
    if(q==1)
    {
        ll x;
        cin>>x;
        if(x==1)
        {
            SUB1 s(n);
            s.calc();
        }
    }
}

Compilation message (stderr)

designated_cities.cpp: In member function 'void SUB1::dfs_down(long long int, long long int)':
designated_cities.cpp:30:16: warning: unused variable 'value_y' [-Wunused-variable]
   30 |             ll value_y=need.value_y;
      |                ^~~~~~~

• Subtask 1: 0 / 6
• Subtask 2: 7 / 7
• Subtask 3: 0 / 9
• Subtask 4: 0 / 17
• Subtask 5: 0 / 17
• Subtask 6: 0 / 44