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답안 #381775

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
381775 2021-03-25T22:05:22 Z oleksg Commuter Pass (JOI18_commuter_pass) C++11
100 / 100
 629 ms 40032 KB 
#pragma GCC optimize("O2")
#include <fstream>
#include <string>
#include <iostream>
#include <bitset>
#include <math.h>
#include <string>
#include <algorithm>
#include <assert.h>
#include <bits/stdc++.h>
#include <vector>
#include <queue>
#include<stdio.h>
#include<ctype.h>
#define ll long long
using namespace std;

struct con{
    ll des;
    ll w;
};

ll n, m;

ll s, t;

ll u, v;

ll dist[100001];
ll used[100001];


ll dpfu[100001];
ll dpbv[100001];

ll used2[100001];
ll dist2[100001];
ll keep[100001];
ll answer = 1e15;
// keep track of all the nodes going to us that can reach us in the minimum distance, later updated to only be nodes that go to us however we also gotta be a usable node that leads back to t
vector<ll> tous[100001];


vector<con> cons[100001];

vector<ll> freeconsfor[100001];
vector<ll> freeconsback[100001];

void dfsdp(ll cur, ll arr[], ll dis[], bool bck){
    used[cur] = 1;
    if (bck){
        arr[cur] = dis[cur];
        for(auto next:freeconsback[cur]){
            if (used[next] == 0){
                used[next] = 1;
                dfsdp(next, arr, dis, bck);
            }
            arr[cur] = min(arr[cur], arr[next]);
        }
    }
    else{
        arr[cur] = dis[cur];
        for(auto next:freeconsfor[cur]){
            if (used[next] == 0){
                used[next] = 1;
                dfsdp(next, arr, dis, bck);
            }
            arr[cur] = min(arr[cur], arr[next]);
        }
    }
}
void dpprocess(){
    for (int x = 0; x < n; x++){
        used[x] = 0;
        dpfu[x] = 1e15;
        dpbv[x] = 1e15;
    }
    dfsdp(t, dpfu, dist, true);
    for (int x = 0; x < n; x++){
        used[x] = 0;
    }
    dfsdp(s, dpbv, dist2, false);
}
struct node{
    ll dist;
    ll cur;
    ll dir;
};

bool Compare(node a, node b)
{
    return a.dist > b.dist;
}

void dfs(int cur){
    keep[cur] = 1;
    for (auto it: tous[cur]){
        if (keep[it] == -1){
            keep[it] = 1;
            dfs(it);
        }
    }
}
int main(){
    /*201503963*/
    //ifstream in("03-07.txt");
    cin >> n >> m >> s >> t >> u >> v;
    s -= 1;
    t -= 1;
    u -= 1;
    v -= 1;
    ll one, two, three;
    for (int x = 0; x < m; x++){
        cin >> one >> two >> three;
        cons[one - 1].push_back({two - 1, three});
        cons[two - 1].push_back({one - 1, three});
    }
    for (int x = 0; x < n; x++){
        dist[x] = 1e15;
        used[x] = -1;
        keep[x] = -1;
    }
    priority_queue<pair<ll, ll>> q;
    dist[s] = 0;
    q.push({0, s});
    while(q.size() > 0){
        ll curdist = q.top().first * -1;
        ll cur = q.top().second;
        q.pop();
        if (used[cur] == -1){
            used[cur] = 1;
            for (auto next: cons[cur]){
                if (dist[next.des] > dist[cur] + next.w){
                    dist[next.des] = dist[cur] + next.w;
                    tous[next.des].clear();
                    tous[next.des].push_back(cur);
                    q.push({-1*dist[next.des], next.des});
                }
                else if (dist[next.des] == dist[cur] + next.w){
                    //partial update
                    tous[next.des].push_back(cur);
                }
            }
        }
    }
    dfs(t);
    for (int x = 0; x < n; x++){
        if (keep[x] == 1){
            for (auto it: tous[x]){
                //cout << x << " " << it << "\n";
                freeconsback[x].push_back(it);
                freeconsfor[it].push_back(x);
                //cout << x << " " << it << " " << "free\n";
            }
        }
    }
    //cout << keep[s] << " " << freeconsfor[s].size() << "\n";
    //dijkstra part 2, this time we know what the free cons are
    for (int x = 0; x < n; x++){
        dist[x]= 1e15;
        used[x] = -1;
    }
    q.push({0, u});
    dist[u] = 0;
    while(q.size() > 0){
        ll curdist = q.top().first * -1;
        ll cur = q.top().second;
        q.pop();
        if (used[cur] == -1){
            used[cur] = 1;
            for (auto next: cons[cur]){
                if (dist[next.des] > dist[cur] + next.w){
                    dist[next.des] = dist[cur] + next.w;

                    q.push({-1*dist[next.des], next.des});
                }
            }
        }
    }
    for (int x = 0; x < n; x++){
        dist2[x]= 1e15;
        used2[x] = -1;
    }
    q.push({0, v});
    dist2[v] = 0;
    while(q.size() > 0){
        ll curdist = q.top().first * -1;
        ll cur = q.top().second;
        q.pop();
        if (used2[cur] == -1){
            used2[cur] = 1;
            for (auto next: cons[cur]){
                if (dist2[next.des] > dist2[cur] + next.w){
                    dist2[next.des] = dist2[cur] + next.w;

                    q.push({-1*dist2[next.des], next.des});
                }
            }
        }
    }
    dpprocess();
    for (int x = 0; x < n; x++){
        answer = min(dpfu[x] + dpbv[x], answer);
    }
    swap(v, u);
    for (int x = 0; x < n; x++){
        ll sw = dist2[x];
        dist2[x] = dist[x];
        dist[x] = sw;
    }
    dpprocess();
    for (int x = 0; x < n; x++){
        answer = min(dpfu[x] + dpbv[x], answer);
    }
    cout << min(answer, dist2[u]) << "\n";

}

Compilation message

commuter_pass.cpp: In function 'int main()':
commuter_pass.cpp:127:12: warning: unused variable 'curdist' [-Wunused-variable]
  127 |         ll curdist = q.top().first * -1;
      |            ^~~~~~~
commuter_pass.cpp:166:12: warning: unused variable 'curdist' [-Wunused-variable]
  166 |         ll curdist = q.top().first * -1;
      |            ^~~~~~~
commuter_pass.cpp:187:12: warning: unused variable 'curdist' [-Wunused-variable]
  187 |         ll curdist = q.top().first * -1;
      |            ^~~~~~~

Subtask #1
16.0 / 16.0

# 결과 실행 시간 메모리 Grader output
1 Correct 448 ms 29276 KB Output is correct
2 Correct 497 ms 31056 KB Output is correct
3 Correct 547 ms 38280 KB Output is correct
4 Correct 470 ms 29404 KB Output is correct
5 Correct 494 ms 32512 KB Output is correct
6 Correct 467 ms 29156 KB Output is correct
7 Correct 558 ms 33096 KB Output is correct
8 Correct 517 ms 32768 KB Output is correct
9 Correct 456 ms 28904 KB Output is correct
10 Correct 452 ms 28640 KB Output is correct
11 Correct 253 ms 29292 KB Output is correct
12 Correct 468 ms 29024 KB Output is correct

Subtask #2
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 523 ms 32952 KB Output is correct
2 Correct 500 ms 33376 KB Output is correct
3 Correct 501 ms 32740 KB Output is correct
4 Correct 505 ms 33256 KB Output is correct
5 Correct 501 ms 34148 KB Output is correct
6 Correct 567 ms 37216 KB Output is correct
7 Correct 559 ms 38240 KB Output is correct
8 Correct 514 ms 33384 KB Output is correct
9 Correct 508 ms 34124 KB Output is correct
10 Correct 497 ms 32740 KB Output is correct
11 Correct 310 ms 32108 KB Output is correct
12 Correct 545 ms 37956 KB Output is correct

Subtask #3
24.0 / 24.0

# 결과 실행 시간 메모리 Grader output
1 Correct 28 ms 11372 KB Output is correct
2 Correct 8 ms 9836 KB Output is correct
3 Correct 8 ms 9836 KB Output is correct
4 Correct 47 ms 12652 KB Output is correct
5 Correct 26 ms 11116 KB Output is correct
6 Correct 8 ms 9836 KB Output is correct
7 Correct 9 ms 9964 KB Output is correct
8 Correct 11 ms 9964 KB Output is correct
9 Correct 9 ms 9836 KB Output is correct
10 Correct 27 ms 11136 KB Output is correct
11 Correct 7 ms 9836 KB Output is correct
12 Correct 7 ms 9836 KB Output is correct
13 Correct 8 ms 9836 KB Output is correct
14 Correct 8 ms 9836 KB Output is correct
15 Correct 8 ms 9836 KB Output is correct

Subtask #4
45.0 / 45.0

# 결과 실행 시간 메모리 Grader output
1 Correct 448 ms 29276 KB Output is correct
2 Correct 497 ms 31056 KB Output is correct
3 Correct 547 ms 38280 KB Output is correct
4 Correct 470 ms 29404 KB Output is correct
5 Correct 494 ms 32512 KB Output is correct
6 Correct 467 ms 29156 KB Output is correct
7 Correct 558 ms 33096 KB Output is correct
8 Correct 517 ms 32768 KB Output is correct
9 Correct 456 ms 28904 KB Output is correct
10 Correct 452 ms 28640 KB Output is correct
11 Correct 253 ms 29292 KB Output is correct
12 Correct 468 ms 29024 KB Output is correct
13 Correct 523 ms 32952 KB Output is correct
14 Correct 500 ms 33376 KB Output is correct
15 Correct 501 ms 32740 KB Output is correct
16 Correct 505 ms 33256 KB Output is correct
17 Correct 501 ms 34148 KB Output is correct
18 Correct 567 ms 37216 KB Output is correct
19 Correct 559 ms 38240 KB Output is correct
20 Correct 514 ms 33384 KB Output is correct
21 Correct 508 ms 34124 KB Output is correct
22 Correct 497 ms 32740 KB Output is correct
23 Correct 310 ms 32108 KB Output is correct
24 Correct 545 ms 37956 KB Output is correct
25 Correct 28 ms 11372 KB Output is correct
26 Correct 8 ms 9836 KB Output is correct
27 Correct 8 ms 9836 KB Output is correct
28 Correct 47 ms 12652 KB Output is correct
29 Correct 26 ms 11116 KB Output is correct
30 Correct 8 ms 9836 KB Output is correct
31 Correct 9 ms 9964 KB Output is correct
32 Correct 11 ms 9964 KB Output is correct
33 Correct 9 ms 9836 KB Output is correct
34 Correct 27 ms 11136 KB Output is correct
35 Correct 7 ms 9836 KB Output is correct
36 Correct 7 ms 9836 KB Output is correct
37 Correct 8 ms 9836 KB Output is correct
38 Correct 8 ms 9836 KB Output is correct
39 Correct 8 ms 9836 KB Output is correct
40 Correct 440 ms 33108 KB Output is correct
41 Correct 470 ms 33120 KB Output is correct
42 Correct 486 ms 33248 KB Output is correct
43 Correct 334 ms 35564 KB Output is correct
44 Correct 364 ms 35680 KB Output is correct
45 Correct 611 ms 39992 KB Output is correct
46 Correct 629 ms 39648 KB Output is correct
47 Correct 505 ms 33628 KB Output is correct
48 Correct 365 ms 32620 KB Output is correct
49 Correct 433 ms 33892 KB Output is correct
50 Correct 577 ms 38532 KB Output is correct
51 Correct 595 ms 40032 KB Output is correct