Submission #926984

#	Time	Username	Problem	Language	Result	Execution time	Memory
926984		vjudge1	Paths (BOI18_paths)	C++17	43 / 100	3070 ms	20948 KiB

paths

#include<bits/stdc++.h>

using namespace std;


const int N = (int)3e5+3;
const int MOD = (int)1e6+3;

int n, m, k, a[N], cnt[6];
vector<int> g[N];
bool used[6];
long long ans;

void dfs(int v) {
	used[a[v]] = 1;
	ans++;
	for(auto to : g[v]) {
		if(!used[a[to]]) {
			dfs(to);
		}
	}
	used[a[v]] = 0;
}

int main() {
    ios_base::sync_with_stdio(NULL);
    cin.tie(0);
	cin >> n >> m >> k;
	for(int i = 1; i <= n; ++i) {
		cin >> a[i];
	}
	for(int i = 1; i <= m; ++i) {
		int u, v;
		cin >> u >> v;
		if(a[u] == a[v]) {
			continue;
		}
		ans += 2;
		g[u].push_back(v);
		g[v].push_back(u);
	}
	if(k > 3) {
	    ans=0;
		for(int i = 1; i <= n; ++i) {
			dfs(i);
		}
		cout << ans-n;
		return 0;
	}
	for(int i = 1; i <= n; ++i) {
		int cur = 0;
		memset(cnt, 0, sizeof(cnt));
		for(auto x : g[i]) {
			ans += 2*(cur-cnt[a[x]]);
			cur++;	
			cnt[a[x]]++;
		}
	}
	cout << ans;
    return 0;
}

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