Submission #72609

#	Time	Username	Problem	Language	Result	Execution time	Memory
72609		claudy	Election Campaign (JOI15_election_campaign)	C++14	100 / 100	999 ms	141968 KiB

election_campaign

# pragma GCC optimize("O3")
# include <bits/stdc++.h>
std::pair<int,int> DR[] = {{-1,0},{0,1},{1,0},{0,-1},{-1,1},{-1,-1},{1,1},{1,-1}};
# define ll long long
# define clock (clock() * 1000.0 / CLOCKS_PER_SEC)
# define rc(s) return cout << s,0
# define rcg(s) cerr << s;exit(0)
# define _ ios_base::sync_with_stdio(false);cin.tie(0);cerr.tie(0);cout.tie(0);
# define db(x) cerr << #x << " = " << x << '\n'
# define pb push_back
# define mp make_pair
# define all(s) s.begin(),s.end()
# define sz(x) (int)((x).size())
# define int ll
using namespace std;

int tin[1 << 17],tout[1 << 17],p[1 << 17][17];
vector<int>vec[1 << 17];
vector<pair<int,int>>clad[1 << 17];
int timer;
int n,a,b,c;
int depth[1 << 17],s[1 << 17][17];
int dp[1 << 17],sum[1 << 17];

struct data
{
    int a,b,c;
};

vector<data>t[1 << 17];

bool upper(int a,int b)
{
    return (tin[a] <= tin[b] && tout[a] >= tout[b]);
}

int lca(int a,int b)
{
    if(upper(a,b)) return a;
    if(upper(b,a)) return b;
    for(int l = 16;l + 1;l--)
    {
        if(!upper(p[a][l],b)) a = p[a][l];
    }
    return p[a][0];
}

void predfs(int nod,int par)
{
    depth[nod] = depth[par] + 1;
    tin[nod] = timer++;
    p[nod][0] = par;
    clad[par].pb(mp(nod,0));
    for(int l = 1;l <= 16;l++)
    {
        p[nod][l] = p[p[nod][l - 1]][l - 1];
        clad[p[nod][l]].pb(mp(nod,l));
    }
    for(auto it : vec[nod])
    {
        if(it != par)
        {
            predfs(it,nod);
        }
    }
    tout[nod] = timer++;
}

int f(int nod,int len)
{
    len--;
    if(len == -1) return 0;
    int ans = sum[nod] - dp[nod];
    for(int i = 16;i >= 0;i--)
    {
        if(len & (1 << i))
        {
            ans += s[nod][i];
            ans -= sum[nod] - dp[nod];
            nod = p[nod][i];
        }
    }
    return ans;
}

void put(int nod)
{
    int x = sum[nod] - dp[nod];
    for(auto it : clad[nod])
    {
        if(it.second == 0)
        {
            s[it.first][0] = x + sum[it.first] - dp[it.first];
        }
        else
        {
            s[it.first][it.second] = s[it.first][it.second - 1] + s[p[it.first][it.second - 1]][it.second - 1] - sum[p[it.first][it.second - 1]] + dp[p[it.first][it.second - 1]];
        }
    }
}

void dfs(int nod,int par)
{
    for(auto it : vec[nod])
    {
        if(it != par){
            dfs(it,nod);
            sum[nod] += dp[it];
        }
    }
    dp[nod] = sum[nod];
    int mx = sum[nod];
    for(auto it : t[nod])
    {
        mx = max(mx,it.c + sum[nod] + f(it.a,depth[it.a] - depth[nod]) + f(it.b,depth[it.b] - depth[nod]));
    }
    dp[nod] = mx;
    put(nod);
}

int32_t main(){_
    //freopen("input","r",stdin);
    cin >> n;
    for(int i = 1;i < n;i++)
    {
        cin >> a >> b;
        a--;
        b--;
        vec[a].pb(b);
        vec[b].pb(a);
    }
    predfs(0,0);
    int q;
    cin >> q;
    while(q--)
    {
        cin >> a >> b >> c;
        a--;
        b--;
        t[lca(a,b)].pb({a,b,c});
    }
    dfs(0,0);
    rc(dp[0]);
}

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