Submission #484605

#	Time	Username	Problem	Language	Result	Execution time	Memory
484605		BackNoob	Robot (JOI21_ho_t4)	C++14	0 / 100	12 ms	24140 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 = 1e3 + 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{
	ll d;
	int pre;
	bool spec;
	int u;
};

struct cmp{
	bool operator()(const item &a , const item &b)
	{
		return a.d > b.d;
	}
};

int n , m;
vector<pair<int , int>> adj[mxN];
int color[mxN];
int cost[mxN];
int cnt[mxN];
ll sumcost[mxN];
ll dist[mxN][mxN][2];

void solve()
{
	cin >> n >> m;
	for(int i = 1 ; i <= m ; i++) {
		int u , v;
		cin >> u >> v >> color[i] >> cost[i];
		adj[u].pb({v , i});
		adj[v].pb({u , i});
	}

	memset(dist , 0x3f , sizeof(dist));
	priority_queue<item , vector<item> , cmp> pq;
	pq.push({0 , 0 , 0 , 1});
	dist[1][0][0] = 0;

	while(!pq.empty()) {
		int u = pq.top().u;
		ll d = pq.top().d;
		int pre = pq.top().pre;
		bool spec = pq.top().spec;
		pq.pop();

		if(d != dist[u][pre][spec]) continue;

		for(auto it : adj[u]) {
			int v = it.fi;
			int c = it.se;
			if(v != pre) {
				cnt[color[c]]++;
				sumcost[color[c]] += cost[c];
			}
			if(v == pre && spec == false) {
				cnt[color[c]]++;
				sumcost[color[c]] += cost[c];
			}
		}

		for(auto it : adj[u]) {
			int v = it.fi;
			int c = it.se;
			if(v == pre) continue;
			if(cnt[color[c]] == 1) {
				if(minimize(dist[v][u][0] , d) == true) {
					pq.push({d , u , 0 , v});
				}
			}
			else {
				if(minimize(dist[v][u][0] , d + sumcost[color[c]] - cost[c])) {
					pq.push({d + sumcost[color[c]] - cost[c] , u , 0 , v});
				}
				if(minimize(dist[v][u][1] , d + cost[c]) == true) {
					pq.push({d + cost[c] , u , 1 , v});
				}
			}
		}

		for(auto it : adj[u]) {
			int v = it.fi;
			int c = it.se;
			if(v != pre) {
				cnt[color[c]]--;
				sumcost[color[c]] -= cost[c];
			}
			if(v == pre && spec == false) {
				cnt[color[c]]--;
				sumcost[color[c]] -= cost[c];
			}
		}
	}

	ll res = dist[0][0][0];
	for(int i = 1 ; i <= n ; i++)
	for(int j = 0 ; j < 2 ; j++) minimize(res , dist[n][i][j]);
	if(res == dist[0][0][0]) cout << -1;
	else cout << res;
}
 
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: 0 / 34
• Subtask 2: 0 / 24
• Subtask 3: 0 / 42