제출 #927171

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
927171		vjudge1	Paths (BOI18_paths)	C++17	23 / 100	146 ms	33752 KiB

paths

#pragma GCC optimize("O3", "unroll-loops") // "Ofast" 	
#pragma GCC target("avx2", "bmi", "bmi2", "lzcnt", "popcnt") 

#include <bits/stdc++.h>

//#define int long long
#define vt vector
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
#define f first
#define s second
#define dbg(x) cerr << #x << " = " << x << '\n'
#define bit(x, i) ((x) >> (i) & 1)

using namespace std;
using ll = long long;
using ld = long double;
using pii = pair<int, int>;

const int N = 1e6 + 5, mod = 1e9 + 7;
const ll inf = 1e18 + 7;
const ld eps = 1e-6;

ll add (ll a, ll b) {
	a += b;
	if (a < 0) a += mod;
	if (a >= mod) a -= mod;
	return a;
}

ll mul (ll a, ll b) {
	a *= b;
	if (a >= mod) a %= mod;
	return a;
}

int n, m, k, a[N], c[5], cnt[5];
vt<int> g[N];

void dfs (int v, int dist = 0) {
	c[dist] = v, cnt[dist]++;
	if (dist > 3) return;
	for (auto to: g[v]) {
		bool ok = 1;
		for (int d = 0; d <= dist; d++) ok &= (to != c[d] && a[to] != a[c[d]]);
		if (ok) dfs(to, dist + 1);
	}
} 

void solve () {
	cin >> n >> m >> k;
	for (int i = 1; i <= n; i++) cin >> a[i];
	int ans = 0;
	for (int i = 1; i <= m; i++) {
		int x, y;
		cin >> x >> y;
		g[x].pb(y), g[y].pb(x);
		if (a[x] != a[y]) ans += 2;
	}
	if (n <= 100) {
		for (int i = 1; i <= n; i++) dfs(i), cnt[0]--;
		cout << (cnt[1] + cnt[2] + cnt[3] + cnt[4]) << '\n';
		return;
	}
	for (int i = 1; i <= n; i++) {
		fill(cnt, cnt + 5, 0);
		for (int j: g[i]) {
			if (a[i] == a[j]) continue;
			cnt[a[j]]++;
		}
		for (int c1 = 1; c1 <= k; c1++) {
			for (int c2 = 1; c2 <= k; c2++) {
				if (c1 == c2) continue;
				ans += cnt[c1] * cnt[c2];
			}
		}
	}
	cout << ans;
	cout << '\n';
}

bool testcases = 0;

signed main() {
#ifdef AMIR
	freopen(".in", "r", stdin);
	freopen(".out", "w", stdout);
#endif
	cin.tie(0) -> sync_with_stdio(0);
	int test = 1;
	if (testcases) cin >> test;
	for (int cs = 1; cs <= test; cs++) {
		solve();
	}
}

• Subtask 1: 23 / 23
• Subtask 2: 0 / 20
• Subtask 3: 0 / 27
• Subtask 4: 0 / 30