Submission #113424

#	Time	Username	Problem	Language	Result	Execution time	Memory
113424		RockyB	Construction of Highway (JOI18_construction)	C++17	7 / 100	2058 ms	3460 KiB

construction

/// In The Name Of God

#include <bits/stdc++.h>

#define f first
#define s second

#define pb push_back
#define pp pop_back
#define mp make_pair

#define sz(x) (int)x.size()
#define sqr(x) ((x) * 1ll * (x))
#define all(x) x.begin(), x.end()

#define rep(i, l, r) for (int i = (l); i <= (r); i++)
#define per(i, l, r) for (int i = (l); i >= (r); i--)

#define Kazakhstan ios_base :: sync_with_stdio(0), cin.tie(0), cout.tie(0);

#define nl '\n'
#define ioi exit(0);

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;

const int N = (int)1e5 + 7;
const int inf = (int)1e9 + 7;
const int mod = (int)1e9 + 7;
const ll linf = (ll)1e18 + 7;

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

using namespace std;

int n;
int a[N];

pair <int, int> e[N];
vector <int> g[N];

int sz[N], up[N], par[N];
void dfs_sz(int v = 1, int p = 0) {
	sz[v]++;
	par[v] = p;
	for (auto &to : g[v]) {
		if (to != p) {
			dfs_sz(to, v);
			sz[v] += sz[to];

			if (sz[to] > sz[g[v][0]]) swap(g[v][0], to);
		}
	}
}
void dfs(int v = 1) {
	for (auto to : g[v]) {
		up[to] = (to == g[v][0] ? up[v] : to);
	}
}
void calc(int v, int u) {
	vector <int> path;
	while (v) {
		path.pb(v);
		v = par[v];
	}
	reverse(all(path));
	ll cnt = 0;
	rep(i, 0, sz(path) - 1) {
		rep(j, i + 1, sz(path) - 1) {
			if (a[path[i]] > a[path[j]]) ++cnt;
		}
		a[path[i]] = a[u];
	}
	cout << cnt << nl;
}
int main() {
	#ifdef IOI2018
		freopen ("in.txt", "r", stdin);
	#endif
	Kazakhstan
	cin >> n;
	rep(i, 1, n) cin >> a[i];
	rep(i, 2, n) {
		cin >> e[i].f >> e[i].s;
		g[e[i].f].pb(e[i].s);
		g[e[i].s].pb(e[i].f);
	}
	dfs_sz();
	up[1] = 1;
	dfs();
	rep(i, 2, n) {
		calc(e[i].f, e[i].s);
	}
	ioi
}

• Subtask 1: 7 / 7
• Subtask 2: 0 / 9
• Subtask 3: 0 / 84