Submission #727502

#	Time	Username	Problem	Language	Result	Execution time	Memory
727502		n0sk1ll	007 (CEOI14_007)	C++17	100 / 100	240 ms	18436 KiB

007

#include <bits/stdc++.h>

#define FAST ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);cerr.tie(0)
#define mp make_pair
#define xx first
#define yy second
#define pb push_back
#define pf push_front
#define popb pop_back
#define popf pop_front
#define all(x) x.begin(),x.end()
#define ff(i,a,b) for (int i = a; i < b; i++)
#define fff(i,a,b) for (int i = a; i <= b; i++)
#define bff(i,a,b) for (int i = b-1; i >= a; i--)
#define bfff(i,a,b) for (int i = b; i >= a; i--)

using namespace std;
long double typedef ld;
unsigned int typedef ui;
long long int typedef li;
pair<int,int> typedef pii;
pair<li,li> typedef pli;
pair<ld,ld> typedef pld;
vector<vector<int>> typedef graph;
unsigned long long int typedef ull;
//const int mod = 998244353;
const int mod = 1000000007;







//Note to self: Check for overflow

graph g(200005);
bool vis[200005];
int duba[200005];
int dubb[200005];

int main()
{
    FAST;

    int n,m; cin>>n>>m;
    int ona,on,a,b; cin>>ona>>on>>a>>b;
    while (m--)
    {
        int u,v; cin>>u>>v;
        g[u].pb(v),g[v].pb(u);
    }

    queue<pii> bfs;

    bfs.push({a,0});
    while (!bfs.empty())
    {
        auto [p,d]=bfs.front(); bfs.pop();
        if (vis[p]) continue; vis[p]=true,duba[p]=d;
        for (auto it : g[p]) bfs.push({it,d+1});
    }

    fff(i,1,n) vis[i]=false;
    bfs.push({b,0});
    while (!bfs.empty())
    {
        auto [p,d]=bfs.front(); bfs.pop();
        if (vis[p]) continue; vis[p]=true,dubb[p]=d;
        for (auto it : g[p]) bfs.push({it,d+1});
    }

    if (duba[on]<duba[ona]) return cout<<-1,0;
    if (dubb[on]<dubb[ona]) return cout<<-1,0;
    if (duba[on]-duba[ona]<dubb[on]-dubb[ona]) return cout<<duba[on]-duba[ona],0;
    if (duba[on]-duba[ona]>dubb[on]-dubb[ona]) return cout<<dubb[on]-dubb[ona],0;

    fff(i,1,n) vis[i]=false;
    int korakona=0;
    bfs.push({ona,0});
    while (!bfs.empty())
    {
        auto [p,d]=bfs.front(); bfs.pop();
        if (vis[p]) continue; vis[p]=true;
        if (d>korakona) korakona=d;
        for (auto it : g[p]) if (duba[it]<duba[p] && dubb[it]<dubb[p]) bfs.push({it,d+1});
    }

    fff(i,1,n) vis[i]=false;
    int korakon=0;
    bfs.push({on,0});
    while (!bfs.empty())
    {
        auto [p,d]=bfs.front(); bfs.pop();
        if (vis[p]) continue; vis[p]=true;
        if (d>korakon) korakon=d;
        for (auto it : g[p]) if (duba[it]<duba[p] && dubb[it]<dubb[p]) bfs.push({it,d+1});
    }

    if (duba[on]-duba[ona]+korakona >= korakon) return cout<<duba[on]-duba[ona],0;
    cout<<duba[on]-duba[ona]-1;
}

//Note to self: Check for overflow

Compilation message (stderr)

007.cpp: In function 'int main()':
007.cpp:60:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   60 |         if (vis[p]) continue; vis[p]=true,duba[p]=d;
      |         ^~
007.cpp:60:31: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   60 |         if (vis[p]) continue; vis[p]=true,duba[p]=d;
      |                               ^~~
007.cpp:69:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   69 |         if (vis[p]) continue; vis[p]=true,dubb[p]=d;
      |         ^~
007.cpp:69:31: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   69 |         if (vis[p]) continue; vis[p]=true,dubb[p]=d;
      |                               ^~~
007.cpp:84:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   84 |         if (vis[p]) continue; vis[p]=true;
      |         ^~
007.cpp:84:31: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   84 |         if (vis[p]) continue; vis[p]=true;
      |                               ^~~
007.cpp:95:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   95 |         if (vis[p]) continue; vis[p]=true;
      |         ^~
007.cpp:95:31: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   95 |         if (vis[p]) continue; vis[p]=true;
      |                               ^~~

• Subtask 1: 30 / 30
• Subtask 2: 70 / 70