Submission #676922

#	Time	Username	Problem	Language	Result	Execution time	Memory
676922		bane	Robot (JOI21_ho_t4)	C++17	0 / 100	3102 ms	517392 KiB

Main

#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <cmath>
#include <complex>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <unordered_set>
#include <vector>
#include <climits>
#include <list>
#include <stack>
using namespace std;
       
using ll = long long;
using db = long double; // or double, if TL is tight
using llu = unsigned long long;
using str = string; // yay python! 
       
// pairs
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using pdb = pair<db,db>;
#define mp make_pair
#define fr first
#define sc second
       
#define tcT template<class T
#define tcTU tcT, class U
// ^ lol this makes everything look weird but I'll try it
tcT> using V = vector<T>; 
tcT, size_t SZ> using AR = array<T,SZ>; 
using vi = V<int>;
using vb = V<bool>;
using vl = V<ll>;
using vd = V<db>;
using vs = V<str>;
using vpi = V<pii>;
using vpl = V<pll>;
using vpd = V<pdb>;
#define ms0(x) memset(x , 0, sizeof(x))
// vectors
// oops size(x), rbegin(x), rend(x) need C++17
#define sz(x) int((x).size())
#define bg(x) begin(x)
#define all(x) bg(x), end(x)
#define rall(x) x.rbegin(), x.rend() 
#define sor(x) sort(all(x)) 
#define rsz resize
#define ins insert 
#define pb push_back
#define eb emplace_back
#define ft front()
#define bk back()
       
#define lb lower_bound
#define ub upper_bound
tcT> int lwb(V<T>& a, const T& b) { return int(lb(all(a),b)-bg(a)); }
tcT> int upb(V<T>& a, const T& b) { return int(ub(all(a),b)-bg(a)); }
       
// loops
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define rep(a) F0R(_,a)
#define each(a,x) for (auto& a: x)
       
const int MOD = (int)1e9+7; // 998244353;
const int MX = (int)2e5+5;
const ll BIG = 1e18; // not too close to LLONG_MAX
const db PI = acos((db)-1);
   
const int dx[4] = {0,1,0,-1};
const int dy[4] = {-1,0,1,0};

long long Robot(int N, int M, vector<vector<pair<int,pair<int,int>>>>roads){
	priority_queue<pair<ll,pair<int,pair<int,int>>>>q;
	q.push(mp(-1,mp(1,mp(1,1))));
	unordered_map<int ,ll>dist[N + 1][2];
	dist[1][1][1] = dist[1][1][0] = 1;
	while(!q.empty()){
		ll dst = -q.top().fr;
		int node = q.top().sc.fr;
		int par = q.top().sc.sc.fr;
		int change = q.top().sc.sc.sc;
		q.pop();
		//cout<<node<<" "<<dst - 1<<endl;
		if (dst != dist[node][change][par]){
			continue;
		}
		unordered_map<int,int>colors;
		for (auto edge : roads[node]){
			if (par == edge.fr && change)continue;
			colors[edge.sc.fr]+=edge.sc.sc;
		}
		for (auto edge : roads[node]){
			if (par == edge.fr)continue;
			if (colors[edge.sc.fr] == edge.sc.sc){
				//it's free
				if (dist[edge.fr][0][node] > dst || dist[edge.fr][0][node]== 0){
					dist[edge.fr][0][node]= dst;
					q.push(mp(-dst, mp(edge.fr, mp(node,0))));
				}
			}else{
				ll best = dst + min(edge.sc.sc, colors[edge.sc.fr] - edge.sc.sc);
				if (dist[edge.fr][1][node]> best || dist[edge.fr][1][node]== 0){
					dist[edge.fr][1][node] = best;
					q.push(mp(-best,mp(edge.fr, mp(node,1))));
				}
			}
		}
	}
	long long ans = 1e18;
	for (int i = 0; i<roads[N].size(); i++){
		long long temp = dist[N][0][roads[N][i].fr];
		if (temp == 0)temp = 1e18;
		if (dist[N][1][roads[N][i].fr] > 0){
			temp = min(temp, dist[N][1][roads[N][i].fr]);
		}
		ans = min(ans, temp - 1);
	}
	return (ans == 1e18 ? -1 : ans);
	
}
 
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
	int N,M;
	cin >> N >> M;
	vector<vector<pair<int,pair<int,int>>>>edges(N + 1);
	for (int i = 0; i<M; i++){
		int a,b,c,p;
		cin >> a >> b >> c >> p;
		edges[a].pb(mp(b,mp(c,p)));
		edges[b].pb(mp(a,mp(c,p)));
	}
	cout<<Robot(N,M,edges);
	return 0;   
}

Compilation message (stderr)

Main.cpp: In function 'long long int Robot(int, int, std::vector<std::vector<std::pair<int, std::pair<int, int> > > >)':
Main.cpp:124:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, std::pair<int, int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  124 |  for (int i = 0; i<roads[N].size(); i++){
      |                  ~^~~~~~~~~~~~~~~~

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