Submission #854422

#TimeUsernameProblemLanguageResultExecution timeMemory
854422nnhzzzCommuter Pass (JOI18_commuter_pass)C++14
15 / 100
2048 ms26292 KiB
// cre: Nguyen Ngoc Hung - Train VOI 2024

#include<bits/stdc++.h>

using namespace std;

#define        __nnhzzz__  signed main()
#define          BIT(i,j)  ((i>>j)&1LL)
#define           MASK(i)  (1LL<<i)
#define            ALL(x)  (x).begin(),(x).end()
#define             SZ(x)  (int)(x).size()
#define                fi  first
#define                se  second
#define                ll  long long
#define               ull  unsigned long long
#define                ld  long double
#define                vi  vector<int>
#define               vvi  vector<vi>
#define              vvvi  vector<vvi>
#define               pii  pair<int,int>
#define              vpii  vector<pii>
#define        REP(i,a,b)  for(int i = (a); i<=(b); ++i)
#define       REPD(i,a,b)  for(int i = (a); i>=(b); --i)
#define   REPDIS(i,a,b,c)  for(int i = (a); i<=(b); i+=c)
#define               int  ll
//-------------------------------------------------------------//
const int oo = 1e16,LOG = 20,MAXN = 1e5+7,N = 1e2+3;
const int MOD = 1e9+7,MOD1 = 1e9+207,MOD2 = 1e9+407,MOD3 = 998244353;
//-------------------------------------------------------------//
template<typename T1, typename T2> bool mini(T1 &a, T2 b){if(a>b){a=b;return true;}return false;}
template<typename T1, typename T2> bool maxi(T1 &a, T2 b){if(a<b){a=b;return true;}return false;}

/*
----------------------------------------------------------------
    END OF TEMPLATE
----------------------------------------------------------------
    Nguyen Ngoc Hung - nnhzzz
    Training for VOI24 gold medal
----------------------------------------------------------------
*/

vpii adj[MAXN];

void dijkstra(int s, int* dis){
    priority_queue<pii,vpii,greater<pii>> heap;
    dis[s] = 0; heap.emplace(0,s);
    while(SZ(heap)!=0){
        auto [w1,u] = heap.top(); heap.pop();
        if(dis[u]!=w1) continue;
        for(auto [v,w]:adj[u]){
            if(mini(dis[v],dis[u]+w)){
                heap.emplace(dis[v],v);
            }
        }
    }
}

int dp[3][MAXN],dis[3][MAXN];

int dfs(int u){
    int res = oo;
    REP(i,0,1) dp[i][u] = dis[i][u];
    for(auto [v,w]:adj[u]){
        if(dis[2][v]==dis[2][u]-w){
            mini(res,dfs(v));
            mini(dp[0][u],dp[0][v]);
            mini(dp[1][u],dp[1][v]);
        }
    }
    mini(res,min(dp[0][u]+dis[1][u],dp[1][u]+dis[0][u]));
    return res;
}

void solve(){
    int n,m,S,T,U,V; cin >> n >> m >> S >> T >> U >> V;
    REP(i,1,m){
        int u,v,w; cin >> u >> v >> w;
        adj[u].emplace_back(v,w);
        adj[v].emplace_back(u,w);
    }
    REP(i,0,2) REP(j,0,n) dp[i][j] = dis[i][j] = oo;
    dijkstra(U,dis[0]);
    dijkstra(V,dis[1]);
    dijkstra(S,dis[2]);
    int res = dis[0][V];
    // cerr << res;
    mini(res,dfs(T));
    cout << res;
}

__nnhzzz__{
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    #define name "test"
    if(fopen(name".inp","r")){
        freopen(name".inp","r",stdin);
        freopen(name".out","w",stdout);
    }
    #define name1 "nnhzzz"
    if(fopen(name1".inp","r")){
        freopen(name1".inp","r",stdin);
        freopen(name1".out","w",stdout);
    }
    int test = 1;
    while(test--){
        solve();
    }
    cerr << "\nTime elapsed: " << 1000*clock()/CLOCKS_PER_SEC << "ms\n";
    return 0;
}

Compilation message (stderr)

commuter_pass.cpp: In function 'void dijkstra(long long int, long long int*)':
commuter_pass.cpp:48:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   48 |         auto [w1,u] = heap.top(); heap.pop();
      |              ^
commuter_pass.cpp:50:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   50 |         for(auto [v,w]:adj[u]){
      |                  ^
commuter_pass.cpp: In function 'long long int dfs(long long int)':
commuter_pass.cpp:63:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   63 |     for(auto [v,w]:adj[u]){
      |              ^
commuter_pass.cpp: In function 'int main()':
commuter_pass.cpp:96:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   96 |         freopen(name".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:97:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   97 |         freopen(name".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:101:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  101 |         freopen(name1".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:102:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  102 |         freopen(name1".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
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