Submission #391816

#	Time	Username	Problem	Language	Result	Execution time	Memory
391816		i_am_noob	007 (CEOI14_007)	C++17	100 / 100	324 ms	33604 KiB

007

#include<bits/stdc++.h>
using namespace std;

#define ll long long
#define int ll
#define rep(n) rep1(i,n)
#define rep1(i,n) rep2(i,0,n)
#define rep2(i,a,b) for(int i=a; i<(b); ++i)
#define rep3(i,a,b) for(int i=a; i>=(b); --i)
#define pb push_back
#define pii pair<int,int>
#define inf 0x3f3f3f3f
#define all(a) a.begin(),a.end()
#define sz(a) ((int)a.size())
#define pow2(x) (1ll<<(x))

#ifdef i_am_noob
#define bug(...) cerr << "#" << __LINE__ << " " << #__VA_ARGS__ << "- ", _do(__VA_ARGS__)
template<typename T> void _do(T x){cerr << x << endl;}
template<typename T, typename ...S> void _do(T x, S ...y){cerr << x << ", ";_do(y...);}
#else
#define bug(...) 49
#endif

const int maxn=200005;

int n,m,a,b,c,d,dis1[maxn],dis2[maxn],dis3[maxn],dis4[maxn],maxx=-1,maxx2=-1,ans;
vector<int> adj[maxn];
queue<int> q;
bool vis[maxn];

signed main(){
    ios_base::sync_with_stdio(0),cin.tie(0);
    cin >> n >> m >> a >> b >> c >> d;
    a--,b--,c--,d--;
    rep(m){
        int u,v;
        cin >> u >> v;
        u--,v--;
        adj[u].pb(v),adj[v].pb(u);
    }
    memset(vis,0,sizeof vis);
    q.push(a);
    vis[a]=1;
    dis1[a]=0;
    while(!q.empty()){
        int u=q.front();
        q.pop();
        for(auto v: adj[u]){
            if(vis[v]) continue;
            q.push(v);
            vis[v]=1;
            dis1[v]=dis1[u]+1;
        }
    }

    memset(vis,0,sizeof vis);
    q.push(b);
    vis[b]=1;
    dis2[b]=0;
    while(!q.empty()){
        int u=q.front();
        q.pop();
        for(auto v: adj[u]){
            if(vis[v]) continue;
            q.push(v);
            vis[v]=1;
            dis2[v]=dis2[u]+1;
        }
    }

    memset(vis,0,sizeof vis);
    q.push(c);
    vis[c]=1;
    dis3[c]=0;
    while(!q.empty()){
        int u=q.front();
        q.pop();
        for(auto v: adj[u]){
            if(vis[v]) continue;
            q.push(v);
            vis[v]=1;
            dis3[v]=dis3[u]+1;
        }
    }

    memset(vis,0,sizeof vis);
    q.push(d);
    vis[d]=1;
    dis4[d]=0;
    while(!q.empty()){
        int u=q.front();
        q.pop();
        for(auto v: adj[u]){
            if(vis[v]) continue;
            q.push(v);
            vis[v]=1;
            dis4[v]=dis4[u]+1;
        }
    }
    bug(dis1[c],dis1[d],dis2[c],dis2[d]);
    if(dis2[c]==dis2[d]){
        rep(n) if(dis3[i]==dis4[i]&&dis3[i]+dis2[i]==dis2[c]) maxx=max(maxx,dis2[i]);
        bug(maxx);
    }

    if(dis1[c]==dis1[d]){
        rep(n) if(dis3[i]==dis4[i]&&dis3[i]+dis1[i]==dis1[c]) maxx2=max(maxx2,dis1[i]);
        bug(maxx2);
    }

    int x=dis2[c],y=dis2[d];

    while(min(dis1[c],dis1[d])<min(x,y)){
        if(x==y){
            if(maxx){
                x--,y--,maxx--;
            }
            else if(dis1[c]>=dis1[d]) x--;
            else y--;
        }
        else x--,y--;
        ans++;
    }

    if(x<dis1[c]||y<dis1[d]){
        cout << ans-1 << "\n";
        return 0;
    }

    if(dis1[c]==dis1[d]){
        if(x!=y) cout << ans << "\n";
        else{
            if(maxx>maxx2) cout << ans-1 << "\n";
            else cout << ans << "\n";
        }
        return 0;
    }

    cout << ans << "\n";
}

Compilation message (stderr)

007.cpp: In function 'int main()':
007.cpp:22:18: warning: statement has no effect [-Wunused-value]
   22 | #define bug(...) 49
      |                  ^~
007.cpp:101:5: note: in expansion of macro 'bug'
  101 |     bug(dis1[c],dis1[d],dis2[c],dis2[d]);
      |     ^~~
007.cpp:22:18: warning: statement has no effect [-Wunused-value]
   22 | #define bug(...) 49
      |                  ^~
007.cpp:104:9: note: in expansion of macro 'bug'
  104 |         bug(maxx);
      |         ^~~
007.cpp:22:18: warning: statement has no effect [-Wunused-value]
   22 | #define bug(...) 49
      |                  ^~
007.cpp:109:9: note: in expansion of macro 'bug'
  109 |         bug(maxx2);
      |         ^~~

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