Submission #1009047

#	Time	Username	Problem	Language	Result	Execution time	Memory
1009047		makanhulia	Commuter Pass (JOI18_commuter_pass)	C++17	0 / 100	598 ms	82956 KiB

commuter_pass

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define fi first
#define se second
#define pb push_back
#define pii pair<int, int>
#define all(x) x.begin(), x.end()
#define ar array<int, 3>
bool ckmin(int& a, int b){return b < a ? a = b, 1 : 0;}
bool ckmax(int& a, int b){return b > a ? a = b, 1 : 0;}
const int N = 2e5 + 5, mod = 1e9 + 7, INF = 1e18;
vector<ar> a[N];
vector<int> e[N];
int dp[N], dp2[N], dp3[N], val[N], vis[N], dp4[N];
map<pii, int> mp, mp2;
signed main(){
    ios_base::sync_with_stdio(0), cin.tie(0);
    int n, m, s, t, u, v; cin >> n >> m >> s >> t >> u >> v;
    priority_queue<pii, vector<pii>, greater<pii>> pq;
    for(int i = 1; i <= m; i++) {
        int x, y, z; cin >> x >> y >> z;
        a[x].pb({y, z, i});
        a[y].pb({x, z, i});
    }
    for(int i = 1; i <= n; i++) dp[i] = dp3[i] = dp2[i] = dp4[i] = INF ;
    pq.push({0, s});
    dp[s] = 0;
    while(!pq.empty()) {
        pii p = pq.top(); pq.pop();
        if(p.fi > dp[p.se]) continue;
        for(auto i : a[p.se]) {
            if(dp[i[0]] > p.fi + i[1]) {
                dp[i[0]] = p.fi + i[1];
                pq.push({dp[i[0]], i[0]});
            }
        }
    }
    int mn = dp[t];
    queue<int> q;
    q.push(t);
    while(!q.empty()) {
        int p = q.front(); q.pop();
        for(auto i : a[p]) {
            // cout << dp[i[0]] << " " << dp[p] << " " << i[0] << " " << i[1] << " " << i[2] << " " << p << endl;
            if(dp[i[0]] + i[1] == dp[p]) {
                if(!val[i[2]]) {
                    mp[{i[0], p}] = 1;
                    mp2[{p, i[0]}] = 1;
                    val[i[2]] = 1;
                    q.push(i[0]);
                }
            }
        }
    }
    pq.push({0, u}); 
    dp2[u] = 0;
    // for(int i = 1; i <= m; i++) cout << val[i] << " ";
    // cout << endl;
    while(!pq.empty()) {
        pii p = pq.top(); pq.pop();
        if(p.fi > dp2[p.se]) continue;
        for(auto i : a[p.se]) {
            if(dp2[i[0]] > p.fi + (mp[{p.se, i[0]}] ? 0 : i[1])) {
                dp2[i[0]] = p.fi + (mp[{p.se, i[0]}] ? 0 : i[1]);
                pq.push({dp2[i[0]], i[0]});
            }
        }
    }
    pq.push({0, u}); 
    while(!pq.empty()) {
        pii p = pq.top(); pq.pop();
        if(p.fi > dp4[p.se]) continue;
        for(auto i : a[p.se]) {
            if(dp4[i[0]] > p.fi + (mp2[{p.se, i[0]}] ? 0 : i[1])) {
                dp4[i[0]] = p.fi + (mp2[{p.se, i[0]}] ? 0 : i[1]);
                pq.push({dp4[i[0]], i[0]});
            }
        }
    }
    // for(int i = 1; i <= n; i++) cout << dp2[i] << " ";
    // cout << endl;
    pq.push({0, v});
    dp3[v] = 0;
    while(!pq.empty()) {
        pii p = pq.top(); pq.pop();
        if(p.fi > dp3[p.se]) continue;
        for(auto i : a[p.se]) {
            if(dp3[i[0]] > p.fi + i[1]) {
                dp3[i[0]] = p.fi + i[1];
                pq.push({dp3[i[0]], i[0]});
            }
        }
    }
    int ans = INF;
    for(int i = 1; i <= n; i++) {
        if(val[i]) {
            ans = min(ans, dp3[i] + min(dp2[i], dp4[i]));
        }
    }
    cout << ans << endl ;
}

Compilation message (stderr)

commuter_pass.cpp: In function 'int main()':
commuter_pass.cpp:39:9: warning: unused variable 'mn' [-Wunused-variable]
   39 |     int mn = dp[t];
      |         ^~

• Subtask 1: 0 / 16
• Subtask 2: 0 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 45