oj.uz

Submission #813520

# Submission time Handle Problem Language Result Execution time Memory
813520 2023-08-07T19:28:44 Z SteGG Commuter Pass (JOI18_commuter_pass) C++17
100 / 100
 278 ms 33852 KB 
#include <bits/stdc++.h>
#define int long long
#define NOT_DONE 1
#define DONE 2

using namespace std;

void open(){
	if(fopen("input.inp", "r")){
		freopen("input.inp", "r", stdin);
		//freopen("output.out", "w", stdout);
	}
}

const int maxn = 1e5 + 5;
const int inf = 3e18;
const int oo = 1e9 + 7;

int n, m;
vector<pair<int, int>> G[maxn];
int S, T;
int U, V;
int min_cost;
int d_s[maxn], d_t[maxn], d_u[maxn], d_v[maxn];
bool in_road[maxn];
int state[maxn];
pair<int, int> dp[maxn]; // trollge

struct Node{
	int index, len;

	Node(){}

	Node(int _index, int _len) : index(_index), len(_len) {}

	bool operator>(const Node &other) const{
		if(len != other.len) return len > other.len;
		return index > other.index;
	}
};

bool check_if_in_road(int u, int v, int w){ // u(S) -> v(T)
	return d_s[u] + w + d_t[v] == min_cost;
}

pair<int, int> custom_min(const pair<int, int> &A, const pair<int, int> &B){
	pair<int, int> result = make_pair(min(A.first, B.first), min(A.second, B.second));
	return result;
}

pair<int, int> custom_cmp(const pair<int, int> &A, const pair<int, int> &B, const pair<int, int> &C){ // compare A < B
	pair<int, int> r1 = custom_min(A, C);
	pair<int, int> r2 = custom_min(B, C);

	if(r1.first + r1.second < r2.first + r2.second) return A;
	else return B;
}

pair<int, int> dfs(int u){
	state[u] = NOT_DONE;
	pair<int, int> result = make_pair(d_u[u], d_v[u]);
	pair<int, int> temp = make_pair(inf, inf);
	for(pair<int, int> node : G[u]){
		int v = node.first;
		int w = node.second;
		if(state[v] == NOT_DONE || !check_if_in_road(u, v, w)) continue;
		if(state[v] == DONE){
			temp = custom_cmp(temp, dp[v], result);
			continue;
		}
		temp = custom_cmp(temp, dfs(v), result);
	}
	state[u] = DONE;

	result = custom_min(result, temp);

	return dp[u] = result;
}

signed main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	open();
	cin >> n >> m;
	cin >> S >> T;
	cin >> U >> V;
	for(int i = 1; i <= m; i++){
		int a, b, c;
		cin >> a >> b >> c;
		G[a].push_back({b, c});
		G[b].push_back({a, c});
	}

	// From s:
	priority_queue<Node, vector<Node>, greater<Node>> pq;
	memset(d_s, oo, sizeof(d_s));
	d_s[S] = 0;
	pq.push({S, 0});
	while(!pq.empty()){
		Node first = pq.top();
		pq.pop();
		int u = first.index;
		if(d_s[u] < first.len) continue;
		for(pair<int, int> node : G[u]){
			int v = node.first;
			int w = node.second;
			if(d_s[v] > d_s[u] + w){
				d_s[v] = d_s[u] + w;
				pq.push({v, d_s[v]});
			}
		}
	}

	// From t:
	memset(d_t, oo, sizeof(d_t));
	d_t[T] = 0;
	pq.push({T, 0});
	while(!pq.empty()){
		Node first = pq.top();
		pq.pop();
		int u = first.index;
		if(d_t[u] < first.len) continue;
		for(pair<int, int> node : G[u]){
			int v = node.first;
			int w = node.second;
			if(d_t[v] > d_t[u] + w){
				d_t[v] = d_t[u] + w;
				pq.push({v, d_t[v]});
			}
		}
	}

	// First handle:
	assert(d_s[T] == d_t[S]);
	min_cost = d_s[T];

	for(int i = 1; i <= n; i++){
		if(d_s[i] + d_t[i] == min_cost){
			in_road[i] = true;
		}
	}

	// From u:
	memset(d_u, oo, sizeof(d_u));
	d_u[U] = 0;
	pq.push({U, 0});
	while(!pq.empty()){
		Node first = pq.top();
		pq.pop();
		int u = first.index;
		if(d_u[u] < first.len) continue;
		for(pair<int, int> node : G[u]){
			int v = node.first;
			int w = node.second;
			if(d_u[v] > d_u[u] + w){
				d_u[v] = d_u[u] + w;
				pq.push({v, d_u[v]});
			}
		}
	}

	// From v:
	memset(d_v, oo, sizeof(d_v));
	d_v[V] = 0;
	pq.push({V, 0});
	while(!pq.empty()){
		Node first = pq.top();
		pq.pop();
		int u = first.index;
		if(d_v[u] < first.len) continue;
		for(pair<int, int> node : G[u]){
			int v = node.first;
			int w = node.second;
			if(d_v[v] > d_v[u] + w){
				d_v[v] = d_v[u] + w;
				pq.push({v, d_v[v]});
			}
		}
	}

	// Last handle:

	// Handle the vertex is in the route:
	pair<int, int> smallest = dfs(S);
	int result = smallest.first + smallest.second;
	for(int i = 1; i <= n; i++){
		if(!in_road[i]){
			result = min(result, d_u[i] + d_v[i]);
		}
	}

	cout << result << endl;

	return 0;
}

Compilation message

commuter_pass.cpp: In function 'void open()':
commuter_pass.cpp:10:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 |   freopen("input.inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 165 ms 21304 KB Output is correct
2 Correct 180 ms 23360 KB Output is correct
3 Correct 210 ms 33852 KB Output is correct
4 Correct 162 ms 22160 KB Output is correct
5 Correct 171 ms 23116 KB Output is correct
6 Correct 171 ms 21356 KB Output is correct
7 Correct 197 ms 23468 KB Output is correct
8 Correct 218 ms 23496 KB Output is correct
9 Correct 213 ms 21552 KB Output is correct
10 Correct 156 ms 21384 KB Output is correct
11 Correct 69 ms 22024 KB Output is correct
12 Correct 203 ms 21536 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 241 ms 27784 KB Output is correct
2 Correct 224 ms 28092 KB Output is correct
3 Correct 228 ms 27156 KB Output is correct
4 Correct 232 ms 27932 KB Output is correct
5 Correct 190 ms 28892 KB Output is correct
6 Correct 196 ms 32732 KB Output is correct
7 Correct 278 ms 33428 KB Output is correct
8 Correct 207 ms 28104 KB Output is correct
9 Correct 225 ms 28992 KB Output is correct
10 Correct 206 ms 27308 KB Output is correct
11 Correct 87 ms 25292 KB Output is correct
12 Correct 204 ms 33360 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 7508 KB Output is correct
2 Correct 3 ms 5844 KB Output is correct
3 Correct 4 ms 5844 KB Output is correct
4 Correct 12 ms 9292 KB Output is correct
5 Correct 7 ms 7552 KB Output is correct
6 Correct 3 ms 5844 KB Output is correct
7 Correct 3 ms 5972 KB Output is correct
8 Correct 4 ms 5972 KB Output is correct
9 Correct 3 ms 5844 KB Output is correct
10 Correct 7 ms 7492 KB Output is correct
11 Correct 2 ms 5844 KB Output is correct
12 Correct 2 ms 5844 KB Output is correct
13 Correct 3 ms 5844 KB Output is correct
14 Correct 3 ms 5844 KB Output is correct
15 Correct 3 ms 5892 KB Output is correct

Subtask #4
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 165 ms 21304 KB Output is correct
2 Correct 180 ms 23360 KB Output is correct
3 Correct 210 ms 33852 KB Output is correct
4 Correct 162 ms 22160 KB Output is correct
5 Correct 171 ms 23116 KB Output is correct
6 Correct 171 ms 21356 KB Output is correct
7 Correct 197 ms 23468 KB Output is correct
8 Correct 218 ms 23496 KB Output is correct
9 Correct 213 ms 21552 KB Output is correct
10 Correct 156 ms 21384 KB Output is correct
11 Correct 69 ms 22024 KB Output is correct
12 Correct 203 ms 21536 KB Output is correct
13 Correct 241 ms 27784 KB Output is correct
14 Correct 224 ms 28092 KB Output is correct
15 Correct 228 ms 27156 KB Output is correct
16 Correct 232 ms 27932 KB Output is correct
17 Correct 190 ms 28892 KB Output is correct
18 Correct 196 ms 32732 KB Output is correct
19 Correct 278 ms 33428 KB Output is correct
20 Correct 207 ms 28104 KB Output is correct
21 Correct 225 ms 28992 KB Output is correct
22 Correct 206 ms 27308 KB Output is correct
23 Correct 87 ms 25292 KB Output is correct
24 Correct 204 ms 33360 KB Output is correct
25 Correct 7 ms 7508 KB Output is correct
26 Correct 3 ms 5844 KB Output is correct
27 Correct 4 ms 5844 KB Output is correct
28 Correct 12 ms 9292 KB Output is correct
29 Correct 7 ms 7552 KB Output is correct
30 Correct 3 ms 5844 KB Output is correct
31 Correct 3 ms 5972 KB Output is correct
32 Correct 4 ms 5972 KB Output is correct
33 Correct 3 ms 5844 KB Output is correct
34 Correct 7 ms 7492 KB Output is correct
35 Correct 2 ms 5844 KB Output is correct
36 Correct 2 ms 5844 KB Output is correct
37 Correct 3 ms 5844 KB Output is correct
38 Correct 3 ms 5844 KB Output is correct
39 Correct 3 ms 5892 KB Output is correct
40 Correct 153 ms 21212 KB Output is correct
41 Correct 167 ms 21624 KB Output is correct
42 Correct 167 ms 21628 KB Output is correct
43 Correct 81 ms 23320 KB Output is correct
44 Correct 88 ms 23360 KB Output is correct
45 Correct 173 ms 22800 KB Output is correct
46 Correct 159 ms 22464 KB Output is correct
47 Correct 183 ms 22100 KB Output is correct
48 Correct 76 ms 17672 KB Output is correct
49 Correct 129 ms 20812 KB Output is correct
50 Correct 183 ms 22944 KB Output is correct
51 Correct 165 ms 22880 KB Output is correct