oj.uz

Submission #400974

# Submission time Handle Problem Language Result Execution time Memory
400974 2021-05-08T23:12:37 Z SirCovidThe19th Commuter Pass (JOI18_commuter_pass) C++14
100 / 100
 550 ms 37360 KB 
#include <bits/stdc++.h>
using namespace std;
 
#define ll long long
#define pll pair<ll, ll>
#define inf LLONG_MAX/(ll)2
 
//nodes, edges, pass start, pass end, person start, person end
ll n, m, s, t, u, v; 
vector<vector<pll>> adj;
//path.first -> dag from s to t, path.second -> dag from t to s
vector<vector<ll>> path[2];
//u dist, v dist
vector<ll> dist[2];
//dp[0][i] -> min cost of u going to node along path start -> i
//dp[1][i] -> min cost of v going to node along path i -> end
vector<ll> dp[2];
 
vector<ll> currDist; vector<vector<ll>> currPath;
 
vector<ll> getDist(ll src){
    priority_queue<pll, vector<pll>, greater<pll>> trav; 
    vector<ll> dst(n); fill(dst.begin(), dst.end(), inf);
    trav.push({0, src}); dst[src] = 0;
    while (!trav.empty()){
        pll curr = trav.top(); trav.pop();
        if (dst[curr.second] != curr.first) continue;
        for (pll elem : adj[curr.second]){
            ll d = curr.first+elem.first;
            if (d < dst[elem.second]){
                dst[elem.second] = d;
                trav.push({d, elem.second});
            }
        }
    }
    return dst;
}
vector<vector<ll>> getPath(ll src){
    priority_queue<pll, vector<pll>, greater<pll>> trav; vector<vector<ll>> par(n); 
    vector<ll> dst(n); fill(dst.begin(), dst.end(), inf);
    trav.push({0, src}); dst[src] = 0;
    while (!trav.empty()){
        pll curr = trav.top(); trav.pop();
        if (dst[curr.second] != curr.first) continue;
        for (pll elem : adj[curr.second]){
            ll d = curr.first+elem.first;
            if (d < dst[elem.second]){
                dst[elem.second] = d;
                par[elem.second].clear(); par[elem.second].push_back(curr.second);
                trav.push({d, elem.second});
            }
            else if (d == dst[elem.second]) 
                par[elem.second].push_back(curr.second);
        }
    }
    return par;
}
//which path -> 0 for backtrack from end, 1 for bactrack from start
//which dist -> 0 for dist from u, 1 for dist from v
ll dfs(ll node, ll whichPath, ll whichDist){
    if (dp[whichDist][node] != inf) return dp[whichDist][node];
    ll lowest = dist[whichDist][node];
    for (ll elem : path[whichPath][node])
        lowest = min(lowest, dfs(elem, whichPath, whichDist));
    dp[whichDist][node] = lowest;
    return lowest;
}
void solve(){
    ll ans = dist[0][v];
    fill(dp[0].begin(), dp[0].end(), inf); fill(dp[1].begin(), dp[1].end(), inf);
    dfs(s, 0, 0);
    dfs(t, 1, 1);
    for (int i = 0; i < n; i++) ans = min(ans, dp[0][i]+dp[1][i]);
    //swap u and v
    fill(dp[0].begin(), dp[0].end(), inf); fill(dp[1].begin(), dp[1].end(), inf);
    dfs(s, 0, 1);
    dfs(t, 1, 0);
    for (int i = 0; i < n; i++) ans = min(ans, dp[0][i]+dp[1][i]);
    cout<<ans;
}

int main(){
    
    cin >> n >> m >> s >> t >> u >> v; s--, t--, u--, v--; 
    adj.resize(n); dp[0].resize(n); dp[1].resize(n);
    
    for (int i = 0; i < m; i++){
        ll a, b, w; cin >> a >> b >> w; a--, b--;
        adj[a].push_back({w, b});
        adj[b].push_back({w, a});
    }
    
    path[0] = getPath(t);
    path[1] = getPath(s);
    dist[0] = getDist(u);
    dist[1] = getDist(v);
    solve();
}

Subtask #1
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 487 ms 30680 KB Output is correct
2 Correct 487 ms 29620 KB Output is correct
3 Correct 522 ms 37360 KB Output is correct
4 Correct 487 ms 33932 KB Output is correct
5 Correct 491 ms 32192 KB Output is correct
6 Correct 495 ms 33512 KB Output is correct
7 Correct 514 ms 32060 KB Output is correct
8 Correct 510 ms 32036 KB Output is correct
9 Correct 493 ms 32688 KB Output is correct
10 Correct 450 ms 32804 KB Output is correct
11 Correct 232 ms 26932 KB Output is correct
12 Correct 505 ms 32572 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 521 ms 31804 KB Output is correct
2 Correct 528 ms 32036 KB Output is correct
3 Correct 513 ms 31484 KB Output is correct
4 Correct 534 ms 32072 KB Output is correct
5 Correct 514 ms 32336 KB Output is correct
6 Correct 513 ms 33924 KB Output is correct
7 Correct 550 ms 34688 KB Output is correct
8 Correct 507 ms 31872 KB Output is correct
9 Correct 519 ms 32368 KB Output is correct
10 Correct 531 ms 31644 KB Output is correct
11 Correct 231 ms 27476 KB Output is correct
12 Correct 513 ms 34196 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 2252 KB Output is correct
2 Correct 2 ms 332 KB Output is correct
3 Correct 2 ms 332 KB Output is correct
4 Correct 43 ms 4080 KB Output is correct
5 Correct 21 ms 1944 KB Output is correct
6 Correct 3 ms 332 KB Output is correct
7 Correct 3 ms 460 KB Output is correct
8 Correct 5 ms 556 KB Output is correct
9 Correct 3 ms 460 KB Output is correct
10 Correct 21 ms 1988 KB Output is correct
11 Correct 1 ms 332 KB Output is correct
12 Correct 2 ms 300 KB Output is correct
13 Correct 2 ms 332 KB Output is correct
14 Correct 2 ms 332 KB Output is correct
15 Correct 2 ms 332 KB Output is correct

Subtask #4
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 487 ms 30680 KB Output is correct
2 Correct 487 ms 29620 KB Output is correct
3 Correct 522 ms 37360 KB Output is correct
4 Correct 487 ms 33932 KB Output is correct
5 Correct 491 ms 32192 KB Output is correct
6 Correct 495 ms 33512 KB Output is correct
7 Correct 514 ms 32060 KB Output is correct
8 Correct 510 ms 32036 KB Output is correct
9 Correct 493 ms 32688 KB Output is correct
10 Correct 450 ms 32804 KB Output is correct
11 Correct 232 ms 26932 KB Output is correct
12 Correct 505 ms 32572 KB Output is correct
13 Correct 521 ms 31804 KB Output is correct
14 Correct 528 ms 32036 KB Output is correct
15 Correct 513 ms 31484 KB Output is correct
16 Correct 534 ms 32072 KB Output is correct
17 Correct 514 ms 32336 KB Output is correct
18 Correct 513 ms 33924 KB Output is correct
19 Correct 550 ms 34688 KB Output is correct
20 Correct 507 ms 31872 KB Output is correct
21 Correct 519 ms 32368 KB Output is correct
22 Correct 531 ms 31644 KB Output is correct
23 Correct 231 ms 27476 KB Output is correct
24 Correct 513 ms 34196 KB Output is correct
25 Correct 23 ms 2252 KB Output is correct
26 Correct 2 ms 332 KB Output is correct
27 Correct 2 ms 332 KB Output is correct
28 Correct 43 ms 4080 KB Output is correct
29 Correct 21 ms 1944 KB Output is correct
30 Correct 3 ms 332 KB Output is correct
31 Correct 3 ms 460 KB Output is correct
32 Correct 5 ms 556 KB Output is correct
33 Correct 3 ms 460 KB Output is correct
34 Correct 21 ms 1988 KB Output is correct
35 Correct 1 ms 332 KB Output is correct
36 Correct 2 ms 300 KB Output is correct
37 Correct 2 ms 332 KB Output is correct
38 Correct 2 ms 332 KB Output is correct
39 Correct 2 ms 332 KB Output is correct
40 Correct 468 ms 33764 KB Output is correct
41 Correct 496 ms 32580 KB Output is correct
42 Correct 507 ms 32724 KB Output is correct
43 Correct 255 ms 27604 KB Output is correct
44 Correct 249 ms 27572 KB Output is correct
45 Correct 520 ms 31984 KB Output is correct
46 Correct 519 ms 32396 KB Output is correct
47 Correct 502 ms 34044 KB Output is correct
48 Correct 266 ms 24544 KB Output is correct
49 Correct 490 ms 35136 KB Output is correct
50 Correct 523 ms 32604 KB Output is correct
51 Correct 543 ms 32536 KB Output is correct