Submission #874375

#	Time	Username	Problem	Language	Result	Execution time	Memory
874375		Irate	A Huge Tower (CEOI10_tower)	C++14	45 / 100	1092 ms	262144 KiB

tower

#include<bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 9;
int n, d;
vector<int>v;
int dp[20][(1 << 20)];
int rec(int indx, int mask){
	int res = 0;
	if(mask == 0)return 1;
	if(dp[indx][mask] != -1)return dp[indx][mask];
	for(int i = 0;i < n;++i){
		if((mask & (1 << i)) && v[indx] + d >= v[i]){
			res += rec(i, mask ^ (1 << i));
			res %= MOD;
		}	
	}
	return dp[indx][mask] = res;
}
vector<vector<int>>G;
vector<bool>vis;
int cnt = 0;
int result = 0;
void dfs(int node){
	vis[node] = 1;
	cnt++;
	if(cnt == n){
		result++;
	}
	for(int &v : G[node]){
		if(!vis[v]){
			dfs(v);
		}
	}
	vis[node] = 0;
	cnt--;
}
int main()
{
    // ios_base::sync_with_stdio(0);
    // cin.tie(0);
    cin >> n >> d;
    v.resize(n);
    for(int i = 0;i < n;++i){
    	cin >> v[i];
    }
    if(n <= 20){
    	int res = 0;
	    for(int i = 0;i < 20;++i){
	    	for(int j = 0;j < (1 << 20);++j){
	    		dp[i][j] = -1;
	    	}
	    }
	    for(int i = 0;i < n;++i){
	    	res += rec(i, ((1 << n) - 1) ^ (1 << i));
	    	res %= MOD;
	    }
	    cout << res;
    }
    else{
    	G.resize(n + 1);
    	vis.resize(n + 1);
    	for(int i = 1;i <= n;++i){
    		for(int j = 1;j <= n;++j){
    			if(i == j)continue;
    			if(v[i - 1] + d >= v[j - 1])G[i].push_back(j);
    		}
    	}
    	for(int i = 1;i <= n;++i){
    		dfs(i);
    	}
    	cout << result;
    }
}

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 5 / 5
• Subtask 5: 5 / 5
• Subtask 6: 5 / 5
• Subtask 7: 5 / 5
• Subtask 8: 5 / 5
• Subtask 9: 5 / 5
• Subtask 10: 0 / 5
• Subtask 11: 0 / 5
• Subtask 12: 0 / 5
• Subtask 13: 0 / 5
• Subtask 14: 0 / 5
• Subtask 15: 0 / 5
• Subtask 16: 0 / 5
• Subtask 17: 0 / 5
• Subtask 18: 0 / 5
• Subtask 19: 0 / 5
• Subtask 20: 0 / 5