Submission #732928

#	Time	Username	Problem	Language	Result	Execution time	Memory
732928		onepunchac168	Election Campaign (JOI15_election_campaign)	C++14	100 / 100	282 ms	47384 KiB

election_campaign

// created by Dinh Manh Hung
// onepunchac168
// THPT CHUYEN HA TINH
// HA TINH, VIET NAM

#include <bits/stdc++.h>
using namespace std;

//#pragma GCC optimize("O3,unroll-loops,no-stack-protector")
//#pragma GCC target("sse4,avx2,fma")
#define task ""
#define ldb long double
#define pb push_back
#define fi first
#define se second
#define pc pop_back()
#define all(x) begin(x),end(x)
#define uniquev(v) v.resize(unique(all(v))-v.begin())
#define FOR(i,a,b) for (int i=a;i<=b;i++)
#define cntbit(v) __builtin_popcountll(v)
#define gcd(a,b) __gcd(a,b)
#define lcm(a,b) ((1LL*a*b)/__gcd(a,b))
#define mask(x) (1LL<<(x))
#define readbit(x,i) ((x>>i)&1)
#define ins insert

typedef long long ll;
typedef pair <ll,ll> ii;
typedef pair <ll,ii> iii;
typedef pair <ii,ii> iiii;

ll dx[]= {1,-1,0,0,1,-1,1,-1};
ll dy[]= {0,0,-1,1,1,-1,-1,1};

const ldb PI = acos (-1);
//const ll mod=978846151;
//const ll base=29;
const int maxn=1e6+5;
const int mod=1e9+7;
const char nl = '\n';
inline int ReadInt()
{
    char co;
    for (co = getchar(); co < '0' || co > '9'; co = getchar());
    int xo = co - '0';
    for (co = getchar(); co >= '0' && co <= '9'; co = getchar())
        xo = xo * 10 + co - '0';
    return xo;
}

void WriteInt(int xo)
{
    if (xo > 9)
        WriteInt(xo / 10);
    putchar(xo % 10 + '0');
}
/* END OF TEMPLATE*/

// ================= Solution =================//
const int N=1e5+5;
ll n,m;
vector <ll> vt[N];
vector <iii> tmp[N];
ll parent[N][20];
ll sz[N];
ll dp[N];
ll in[N];
ll out[N];
ll root=0;
ll bit[N];
void update(int u,ll val)
{
    while (u<=n)
    {
        bit[u]+=val;
        u+=u&(-u);
    }
}
ll get(int u)
{
    ll suma=0;
    while (u>0)
    {
        suma+=bit[u];
        u-=u&(-u);
    }
    return suma;
}
void dfsa(int u,int vv)
{
    in[u]=++root;
    for (auto v:vt[u])
    {
        if (v==vv)
        {
            continue;
        }
        parent[v][0]=u;
        for (int i=1;i<=18;i++)
        {
            parent[v][i]=parent[parent[v][i-1]][i-1];
        }
        sz[v]=sz[u]+1;
        dfsa(v,u);
    }
    out[u]=root;
}
ll par[N];
ll findpar(int u)
{
    if (par[u]<0)
    {
        return u;
    }
    return par[u]=findpar(par[u]);
}
void dfs(int u,int vv)
{
    ll sum=0;
    for (auto v:vt[u])
    {
        if (v==vv)
        {
            continue;
        }
        dfs(v,u);
        dp[u]=max(dp[u],dp[v]);
        sum+=dp[v];
    }
    ll gmax=0;
    for (auto v:tmp[u])
    {
        ll ua=v.se.fi;
        ll va=v.se.se;
        ll wa=v.fi;
        ll indexa=get(in[ua])+get(in[va]);
        ll indexb=sum;
        ll a1=findpar(ua);
        ll a2=findpar(va);
        if (a1!=u)
        {
            indexb-=dp[a1];
        }
        if (a2!=u)
        {
            indexb-=dp[a2];
        }
        gmax=max(gmax,indexa+indexb+wa);
    }
    dp[u]=max({dp[u],gmax,sum});
    update(in[u],sum);
    update(in[u]+1,-sum);
    for (auto v:vt[u])
    {
        if (v==vv)
        {
            continue;
        }
        update(in[v],sum-dp[v]);
        update(out[v]+1,-sum+dp[v]);
        par[v]=u;
    }
}
ll lca(int u,int v)
{
    if (sz[u]>sz[v])
    {
        swap(u,v);
    }
    for (int i=18;i>=0;i--)
    {
        if (sz[v]-mask(i)>=sz[u])
        {
            v=parent[v][i];
        }
    }
    if (u==v){return u;}
    for (int i=18;i>=0;i--)
    {
        if (parent[u][i]!=parent[v][i])
        {
            u=parent[u][i];
            v=parent[v][i];
        }
    }
    if (u!=v)
    {
        u=parent[u][0];
        v=parent[v][0];
    }
    return u;
}
void optmushnpr()
{
    cin>>n;
    for (int i=1;i<=n;i++)
    {
        par[i]=-1;
    }
    for (int i=1;i<n;i++)
    {
        ll u,v;
        cin>>u>>v;
        vt[u].pb(v);
        vt[v].pb(u);
    }
    dfsa(1,-1);
    cin>>m;
    for (int i=1;i<=m;i++)
    {
        ll a,b,c;
        cin>>a>>b>>c;
        ll pp=lca(a,b);
        tmp[pp].pb({c,{a,b}});
    }
    dfs(1,-1);
    cout<<dp[1];
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    if (fopen(task".inp","r")){
    freopen(task".inp","r",stdin);
    freopen(task".out","w",stdout);}
    int t;
    t=1;
    //cin>>t;
    while (t--){optmushnpr();}
}

// goodbye see ya

Compilation message (stderr)

election_campaign.cpp: In function 'int main()':
election_campaign.cpp:225:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  225 |     freopen(task".inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
election_campaign.cpp:226:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  226 |     freopen(task".out","w",stdout);}
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 30 / 30
• Subtask 5: 10 / 10
• Subtask 6: 40 / 40