Submission #571585

#	Time	Username	Problem	Language	Result	Execution time	Memory
571585		teki	Paprike (COI18_paprike)	C++11	100 / 100	71 ms	19404 KiB

paprike

#include <bits/stdc++.h>

typedef long long ll;

#define pb push_back
#define MS(x,y) memset((x),(y),sizeof((x)))
#define MN 1000000001

using namespace std;

const ll nsize = 100001;
ll n,m,q;
ll parent[nsize];
ll sajz[nsize];
vector<ll> pat[nsize];
bool vis[nsize];
ll vred[nsize];

void dfsConst(ll pos, ll parnt) {
    if (vis[pos]) return;

    vis[pos] = true;
    parent[pos] = parnt;

    for (auto it:pat[pos]) dfsConst(it,pos);
}

bool custComp(ll a, ll b) {
    if (sajz[a] == sajz[b]) return a > b;

    return sajz[a] < sajz[b];
}

ll res = 0;

void dfs(ll pos) {
    vector<ll> deca;
    ll bris = pat[pos].size()-1;
    if (pos == 0) bris++;

    for (auto it:pat[pos]) {
        if (it == parent[pos]) continue;

        dfs(it);
        deca.pb(sajz[it]);
    }

    sort(deca.begin(),deca.end());
    for (auto it:deca) {
        if (sajz[pos]+it <= q) {
            sajz[pos] += it;
            bris--;
        } else {
            res += bris;
            return;
        }
    }
}

int main()
{
    #if LOCAL_DEBUG
        fstream cin("in.txt");
    #endif

    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    ll zbir = 0;

    cin>>n>>q;
    m = n-1;

    for (ll i = 0; i<n; i++) cin>>vred[i];
    for (ll i = 0; i<n; i++) zbir += vred[i];

    for (ll i = 0; i<m; i++) {
        ll a,b;
        cin>>a>>b;
        a--; b--;

        pat[a].pb(b);
        pat[b].pb(a);
    }

    MS(vis,0);
    for (ll i = 0; i<n; i++) sajz[i] = vred[i];
    dfsConst(0,0);

    dfs(0);

    if (zbir <= q) {
        cout<<0<<endl;
        return 0;
    }

    cout<<res<<endl;
}

• Subtask 1: 11 / 11
• Subtask 2: 13 / 13
• Subtask 3: 27 / 27
• Subtask 4: 49 / 49