Submission #319096

#	Time	Username	Problem	Language	Result	Execution time	Memory
319096		Foxyy	Paprike (COI18_paprike)	C++14	100 / 100	73 ms	17636 KiB

paprike

//#define DEBUG

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

const int MAXN = 100000;
const int INF = 0x3f3f3f3f, MOD = 1000000007;
#define INIT(arr, val) fill(arr, arr+(int)(sizeof(arr)/sizeof(arr[0])), val)
#define REP(i, lb, rb, inc) for(int i = (lb); i < (rb); i += inc)
#define RREP(i, rb, lb, dec) for(int i = (rb)-1; i >= (lb); i -= dec)
typedef long long ll;
#define sz size()
typedef stack<int, vector<int> > SI;
typedef queue<int> QI;
typedef vector<int> VI;
#define pb push_back
typedef pair<int, int> PII;
#define mp make_pair
#define F first
#define S second
#define endl '\n'
#define dbg(a, b) cerr << "dbg: a " << b << endl;
#define dbg_itv(a, b, c) cerr << "dbg_itv: " << a << " " << b << " : " << c << endl
#define IOS() cin.tie(0); cout.sync_with_stdio(0)

int n, k;

int ans;

ll w[MAXN];
VI g[MAXN];

// solve() returns the maximum cost of the child tree
ll solve(int u = 0, int anc = 0) {
	vector<ll> chld;
	for (int v : g[u]) {
		if (v == anc) continue;
		ll ret = solve(v, u);
		chld.pb(ret);
	}
	ll cur = w[u];
	sort(chld.begin(), chld.end());
	REP(i, 0, chld.size(), 1) {
		cur += chld[i];
		if (cur > k) {
			cur -= chld[i];
			ans += (chld.size()-i);
			break;
		}
	}
	return cur;
}

signed main() {
	IOS();
	cin >> n >> k;
	REP(i, 0, n, 1) cin >> w[i];
	int u, v;
	REP(i, 0, n-1, 1) {
		cin >> u >> v;
		u--, v--;
		g[u].pb(v); g[v].pb(u);
	}
	
	solve();
	cout << ans << endl;
}

Compilation message (stderr)

paprike.cpp: In function 'll solve(int, int)':
paprike.cpp:9:49: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    9 | #define REP(i, lb, rb, inc) for(int i = (lb); i < (rb); i += inc)
      |                                                 ^
paprike.cpp:43:2: note: in expansion of macro 'REP'
   43 |  REP(i, 0, chld.size(), 1) {
      |  ^~~

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