Submission #484751

#	Time	Username	Problem	Language	Result	Execution time	Memory
484751		BackNoob	Robot (JOI21_ho_t4)	C++14	34 / 100	3081 ms	49240 KiB

Main

#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define endl '\n'
#define MASK(i) (1LL << (i))
#define ull unsigned long long
#define ld long double
#define pb push_back
#define all(x) (x).begin() , (x).end()
#define BIT(x , i) ((x >> (i)) & 1) 
#define TASK "task"
#define sz(s) (int) (s).size()
 
using namespace std;
const int mxN = 3e5 + 227;
const int inf = 1e9 + 277;
const int mod = 1e9 + 7;
const ll infll = 1e18 + 7;
const int base = 307;
const int LOG = 20;
 
template <typename T1, typename T2> bool minimize(T1 &a, T2 b) {
	if (a > b) {a = b; return true;} return false;
}
template <typename T1, typename T2> bool maximize(T1 &a, T2 b) {
	if (a < b) {a = b; return true;} return false;
}
 
struct item{
	int u;
	int pre;
	ll d;
};
 
struct cmp{
	bool operator()(const item &a , const item &b)
	{
		return a.d > b.d;
	}
};
 
struct EDGE{
	int v , color , cost;
};
 
int n , m;
vector<EDGE> adj[mxN];
ll dist[mxN];
map<int , ll> dp[mxN];
int cnt[mxN];
ll sumcost[mxN];
 
void solve()
{
	cin >> n >> m;
	for(int i = 1 ; i <= m ; i++) {
		int u , v , color , cost;
		cin >> u >> v >> color >> cost;
		adj[u].pb({v , color , cost});
		adj[v].pb({u , color , cost});
	}
 	
	memset(dist , 0x3f , sizeof(dist));
	priority_queue<item , vector<item> , cmp> pq;
	pq.push({1 , 0 , dist[1] = 0});
	while(!pq.empty()) {
		int u , pre;
		ll d;
		u = pq.top().u;
		pre = pq.top().pre;
		d = pq.top().d;
		pq.pop();
 
		if(pre == 0 && dist[u] != d) continue;
		if(pre != 0 && dp[u][pre] != d) continue;
 
		for(auto it : adj[u]) {
			if(it.v == pre) continue;
			cnt[it.color]++;
			sumcost[it.color] += it.cost;
		}
		for(auto it : adj[u]) {
			if(it.v == pre) continue;
			if(cnt[it.color] == 1) {
				if(minimize(dist[it.v] , d) == true) {
					pq.push({it.v , 0 , d});
				}
			}	
			else{
				if(!dp[it.v].count(u) || dp[it.v][u] > d + it.cost) {
					dp[it.v][u] = d + it.cost;
					pq.push({it.v , u , d + it.cost});
				}
				if(minimize(dist[it.v] , d + sumcost[it.color] - it.cost) == true) {
					pq.push({it.v , 0 , d + sumcost[it.color] - it.cost});
				}
			}
		}
 
		for(auto it : adj[u]) {
			if(it.v == pre) continue;
			cnt[it.color]--;
			sumcost[it.color] -= it.cost;
		}
	}
	ll ans = dist[n];
	for(int i = 1 ; i <= n ; i++) {
		if(dp[n].count(i) > 0) minimize(ans , dp[n][i]);
	}
	if(ans == dist[0]) cout << -1;
	else cout << ans;
}
 
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    //freopen(TASK".inp" , "r" , stdin);
    //freopen(TASK".out" , "w" , stdout);
    
    int tc = 1;
    //cin >> tc;
    while(tc--) {
    	solve();
    }
    return 0;
}

• Subtask 1: 34 / 34
• Subtask 2: 0 / 24
• Subtask 3: 0 / 42