제출 #1254477

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1254477		thdh__	Cities (BOI16_cities)	C++20	100 / 100	1657 ms	42220 KiB

cities

#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define eb emplace_back
#define pu push
#define ins insert
#define fi first
#define se second
#define all(a) a.begin(),a.end()
#define bruh ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define fu(x,a,b) for (auto x=a;x<=b;x++)
#define fd(x,a,b) for (auto x=a;x>=b;x--)
#define int ll

using namespace std;
//mt19937 mt(chrono::steady_clock::now().time_since_epoch().count());

/*
Competitive Programming notes that I need to study & fix my dumbass self:

1. Coding:
- Always be sure to check the memory of arrays (maybe use vectors), for loops
- Always try to maximize the memory if possible, even if you are going for subtasks
- Do not exploit #define int long long, it will kill you

2. Stress: 
- Always try generating big testcases and try if they run

3. Time management:
- Don't overcommit or undercommit, always spend a certain amount of time to think a problem, don't just look at it and say I'm fucked
- Do not spend too much time coding brute-force solutions, they should be easily-codable solutions that don't take up too much time

Time management schedule:
Offline / LAH days (4 problems - 3h):
15' thinking of solution / idea
1. no idea: skip
2. yes idea: continue thinking for <= 15'

+ implementing: <= 20'
+ brute-force: <= 5'
+ test generator: <= 5'

I hate offline because I am dumb
*/

typedef pair<int, int> ii;
const int N = 1e5+5;
const int B = 750;
const int mod = 1e9+7;
const int inf = 1e18;
using cd = complex<double>;
const long double PI = acos(-1);
int power(int a,int b) {ll x = 1;if (a >= mod) a%=mod; while (b) {if (b & 1) x = x*a % mod;a = a*a % mod;b>>=1;}return x;} 

int n,k,m;
int a[10], id[N];
bool check[N];
vector<ii> adj[N];
int dp[50][N], d[N];
priority_queue<ii, vector<ii>, greater<ii>> q;

void dijkstra(int mask) 
{
	while (!q.empty()) 
	{
		int dist = q.top().fi, u = q.top().se;
		q.pop();
		if (dist != dp[mask][u]) continue;
		for (auto i : adj[u]) 
		{
			int v = i.fi, w = i.se;
			int nmask = mask;
			if (check[v]) nmask |= (1<<id[v]);
			if (dist+w < dp[nmask][v]) 
			{
				dp[nmask][v] = dist+w;
				if (nmask == mask) q.push({dp[nmask][v], v});
			}
		}
	}
}

void solve()
{
	cin>>n>>k>>m;
	for (int i = 0; i < k; i++) cin>>a[i], check[a[i]] = 1, id[a[i]] = i;
	for (int i = 0; i < m; i++) 
	{
		int u,v,w; cin>>u>>v>>w;
		adj[u].pb({v, w}); adj[v].pb({u, w});
	}
	for (int mask = 0; mask < (1<<k); mask++) for (int i = 1; i <= n; i++) dp[mask][i] = inf;
	for (int i = 1; i <= n; i++) dp[0][i] = 0;
	for (int i = 0; i < k; i++) dp[(1<<i)][a[i]] = 0;
	for (int mask = 0; mask < (1<<k); mask++) 
	{
		for (int sub = mask; sub; sub = (sub-1) & mask) for (int i = 1; i <= n; i++) dp[mask][i] = min(dp[mask][i], dp[sub][i] + dp[mask ^ sub][i]);
		for (int i = 1; i <= n; i++) if (dp[mask][i] != inf) q.push({dp[mask][i], i});
		dijkstra(mask);
		// cout<<mask<<endl;
		// for (int i = 1; i <= n; i++) cout<<dp[mask][i]<<" ";
		// cout<<endl;
	}
	int ans = inf;
	for (int i = 1; i <= n; i++) ans = min(ans, dp[(1<<k)-1][i]);
	cout<<ans;
}

/*
Go through the mistakes you usually make and revise your code, for god's sake...
*/

signed main()
{
	bruh
	//freopen("input.inp","r",stdin);
	//freopen("output.inp","w",stdout);
	int t = 1;
	// cin>>t;
	while (t--)
	{
		solve();
		cout<<"\n";
	}
}

• Subtask 1: 22 / 22
• Subtask 2: 14 / 14
• Subtask 3: 15 / 15
• Subtask 4: 23 / 23
• Subtask 5: 26 / 26