Submission #227631

#	Time	Username	Problem	Language	Result	Execution time	Memory
227631		bensonlzl	Paths (BOI18_paths)	C++14	100 / 100	656 ms	172408 KiB

paths

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

ll sum = 0, dp[2][300005][(1 << 5)];
vector<int> AdjList[300005];
int N, M, K, X, Y, colour[300005];

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cin >> N >> M >> K;
	for (int i = 1; i <= N; ++i){
		cin >> colour[i];
		colour[i]--;
	}
	for (int i = 1; i <= M; ++i){
		cin >> X >> Y;
		AdjList[X].push_back(Y);
		AdjList[Y].push_back(X);
	}
	for (int i = 1; i <= N; ++i){
		for (int mask = 0; mask < (1 << 5); ++mask){
			dp[0][i][mask] = dp[1][i][mask] = 0;
		}
		dp[0][i][(1 << colour[i])] = 1;
	}
	for (int i = 1; i < K; ++i){
		for (int v = 1; v <= N; ++v){
			for (int mask = 0; mask < (1 << 5); ++mask){
				dp[i&1][v][mask] = 0;
				if ((mask & (1 << colour[v])) == 0) continue;
				for (auto it : AdjList[v]){
					dp[i&1][v][mask] += dp[(i-1)&1][it][mask ^ (1 << colour[v])];
				}
				sum += dp[i&1][v][mask];
			}
		}
	}
	cout << sum << '\n';
}

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