Submission #696119

#	Time	Username	Problem	Language	Result	Execution time	Memory
696119		jiahng	Election Campaign (JOI15_election_campaign)	C++14	100 / 100	217 ms	45012 KiB

election_campaign

#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
#define int ll
typedef pair<int, int> pi;
typedef vector <int> vi;
typedef vector <pi> vpi;
typedef pair<pi, ll> pii;
typedef set <ll> si;
typedef long double ld;
#define f first
#define s second
#define mp make_pair
#define FOR(i,s,e) for(int i=s;i<=int(e);++i)
#define DEC(i,s,e) for(int i=s;i>=int(e);--i)
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define lbd(x, y) lower_bound(all(x), y)
#define ubd(x, y) upper_bound(all(x), y)
#define aFOR(i,x) for (auto i: x)
#define mem(x,i) memset(x,i,sizeof x)
#define fast ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0)
#define maxn 200010
#define INF (int)1e9
#define MOD 998244353
typedef pair <vi, int> pvi;
typedef pair <int,pi> ipi;
typedef vector <pii> vpii;
#define DEBUG 0

int TC,N,K;
int depth[maxn],twok[maxn][20],st[maxn],en[maxn];
vector <pii> A[maxn];
int M;
int a,b,c;
vi adj[maxn];
int co = 1;
struct FW{
    int fw[maxn],N;
    FW(int _N){
        N = _N; FOR(i,1,N) fw[i] = 0;
    }
    void update(int p,int v){
        for (int i=p;i<=N;i+=i&(-i)) fw[i] += v;
    }
    void upd(int a,int b,int c){
        update(a,c); update(b+1,-c);
    }
    int qry(int p){
        int ans = 0;
        for (int i=p;i>0;i-=i&(-i)) ans += fw[i];
        return ans;
    }
}*fw;
void dfs(int x,int p){
    twok[x][0] = p;
    st[x] = co++;
    aFOR(i, adj[x]) if (i != p){
        depth[i] = depth[x] + 1; dfs(i,x);
    }
    en[x] = co - 1;
}
int kpar(int x,int k){
    FOR(i,0,19) if (k &(1<<i)) x = twok[x][k];
    return x;
}
int lca(int a,int b){
    if (depth[a] < depth[b]) swap(a,b);
    int d = depth[a] - depth[b];
    FOR(i,0,19) if ((1<<i)&d) a = twok[a][i];
    if (a == b) return a;

    DEC(i,19,0) if (twok[a][i] != twok[b][i]){
        a = twok[a][i]; b = twok[b][i];
    }
    return twok[a][0];
}
int dp[maxn];
void compdp(int x,int p){
    aFOR(i,adj[x]) if (i != p) compdp(i,x);

    int sm = 0;
    aFOR(i,adj[x]) if (i != p) sm += dp[i];
    dp[x] = sm;
    aFOR(i,A[x]){
        int a = i.f.f, b = i.f.s, c = i.s;
        int res = c + sm;

        if (a != x){
            int ap = kpar(a,depth[a]-depth[x]-1);
            res += fw->qry(st[a]) - fw->qry(st[x]);
        }
        if (b != x){
            int bp = kpar(b,depth[b]-depth[x]-1);
            res += fw->qry(st[b]) - fw->qry(st[x]);
        }
        dp[x] = max(dp[x], res);
    }

    fw->upd(st[x], en[x], sm - dp[x]);
}
int32_t main(){
    fast;
    cin >> N;
    FOR(i,1,N-1){
        cin >> a >> b; adj[a].pb(b); adj[b].pb(a);
    }
    dfs(1,-1);
    FOR(k,1,19){
        FOR(i,1,N){
            if (twok[i][k-1] == -1) twok[i][k] = -1;
            else twok[i][k] = twok[twok[i][k-1]][k-1];
        }
    }
    cin >> M;
    FOR(i,1,M){
        cin >> a >> b >> c;
        A[lca(a,b)].pb(pii(pi(a,b), c));
    }
    fw = new FW(N);
    compdp(1,-1);
    cout << dp[1];
}

Compilation message (stderr)

election_campaign.cpp: In function 'void compdp(ll, ll)':
election_campaign.cpp:91:17: warning: unused variable 'ap' [-Wunused-variable]
   91 |             int ap = kpar(a,depth[a]-depth[x]-1);
      |                 ^~
election_campaign.cpp:95:17: warning: unused variable 'bp' [-Wunused-variable]
   95 |             int bp = kpar(b,depth[b]-depth[x]-1);
      |                 ^~

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