Submission #1311667

#	Time	Username	Problem	Language	Result	Execution time	Memory
1311667		modwwe	Mousetrap (CEOI17_mousetrap)	C++20	0 / 100	214 ms	110108 KiB

mousetrap

#pragma GCC optimize("Ofast,unroll-loops")
#include <bits/stdc++.h>
#define int long long
#define ll long long
#define ull unsigned long long
#define down cout<<'\n';
#define debug cout<<" cucuucucuuu",down
#define modwwe  int t;cin>>t; while(t--)
#define bit(i,j) (i>>j&1)
#define sobit(a) __builtin_popcountll(a)
#define task2 "top1apio"
#define task "test"
#define fin(x) freopen(x".inp","r",stdin)
#define fou(x) freopen(x".out","w",stdout)
#define pb push_back
#define mask(k) (1ll<<k)
#define checktime   cerr <<  (double)clock() / CLOCKS_PER_SEC * 1000  << " ms";
using namespace std;
#define getchar_unlocked getchar
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
using i128 = __int128;
int rand(int l, int r)
{
    return uniform_int_distribution<int>(l, r)(rd);
}
void phongbeo();
const int inf = 1e9;
const int mod2 = 998244353;
//const ll base=67;
ll  n, m, s1, s2, s4, s3, sf, k, s5, s6, s7, s8, s9, mx2, res, dem2 = 0, dem = 0, s33, dem3, dem4, mid, l2,
                                                               r2, center;
ll  i, s10, s12, k1, k2, k3, s11, lim, w, l, r, dem5, dem6, dem7, dem9, root;
ll el = 19;
main()
{
    ///top1apio
    if (fopen(task2".inp", "r"))
    {
        fin(task2);
        fou(task2);
    }
    ///top1apio
    if (fopen(task".inp", "r"))
    {
        fin(task);
        fou(task);
    }

    ///top1apio
    ios_base::sync_with_stdio(0);
    cout.tie(0);
    cin.tie(0);
    // cin>>s1;
    ll t=1;
    //cin>>t;
    s10=t;
    while(t--)
        phongbeo();
    ///  checktime
    ///top1apio
}
int in[1000001],ou[1000001],par[1000001],dep[1000001],dp[1000001],ans[1000001];
int cost[1000001];
vector<int> v[1000001];
bool check(int x,int y)
{
    if(in[x]<=in[y]&&in[y]<=ou[x])return 1;
    return 0;
}
void dfs(int x,int y)
{
    in[x]=++dem;
    if(x!=m)
        dep[x]=dep[y]+(v[x].size()-1);
    par[x]=y;
    for(auto f:v[x])
        if(f^y)
        {
            dfs(f,x);
        }
    ou[x]=dem;
}
void des(int x,int y)
{
    for(auto f:v[x])
        if(f^y)
            des(f,x);
    if(v[x].size()==1||v[x].size()==2)
    {
        cost[x]=dep[x];
        return;
    }
    s3=-1;
    s5=0;
    for(auto f:v[x])
        if(f^y&&dep[f]>s3)
            s3=dep[f],s5=f;
    s3=-1;
    for(auto f:v[x])
        if(f^y&&f^s5)
            s3=max(s3,dep[f]);
    cost[x]=s3;
}
bool dg(int x,int y,int mx,int lx)
{
    if(dep[x]>lx)return 0;
    int s=0;
    for(auto f:v[x])
    if(f^y&&cost[f]<=lx)s++;
    if(s<=mx+1)return 1;
    return 0;
}
bool check(int x)
{
    int lst=0;
    s5=0;
    int lim=k;
    while(true)
    {
        s5++;
        bool ok=0;
        for(auto f:v[lim])
            if(f^par[lim]&&f^lst)
            {
                if(s5>=v[lim].size()-3+(lst==0))
                    if(dg(f,lim,s5-v[lim].size()+3-(lst==0),x+(lst!=0)))
                    {
                        ok=1;
                        break;
                    }
            }
        if(!ok)
        {
            s5=s5-(v[lim].size()-1)+(lst!=0);
            x-=(v[lim].size()-1)+(lst!=0);
        }
        else
        {
            dem=dem2=0;
            for(auto f:v[lim])
                if(f^par[lim]&&f^lst)
                {
                    if(cost[f]>x+(lst!=0))
                    {
                        dem++;
                        break;
                    }
                    dem2++;
                }
            if(dem2==dem)
            {
                dem--;
            }
            s5-=dem;
            x-=dem;
        }
        if(s5<0||x<0)return 0;
        lim=par[lim];
        if(lim==m)break;
    }
    return 1;
}
void phongbeo()
{
    cin>>n>>m>>k;
    for(int i=1; i<=n; i++)ans[i]=inf;
    for(int i=1; i<n; i++)
        cin>>l>>r,v[l].pb(r),v[r].pb(l);
    dfs(m,0);
    des(m,0);
    l=0;
    r=n-1;
    while(l<=r)
    {
        int mid=l+r>>1;
        if(!check(mid))l=mid+1;
        else r=mid-1;
    }
    cout<<l-1;
}

Compilation message (stderr)

mousetrap.cpp:34:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   34 | main()
      | ^~~~
mousetrap.cpp: In function 'int main()':
mousetrap.cpp:13:23: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 | #define fin(x) freopen(x".inp","r",stdin)
      |                ~~~~~~~^~~~~~~~~~~~~~~~~~~
mousetrap.cpp:39:9: note: in expansion of macro 'fin'
   39 |         fin(task2);
      |         ^~~
mousetrap.cpp:14:23: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 | #define fou(x) freopen(x".out","w",stdout)
      |                ~~~~~~~^~~~~~~~~~~~~~~~~~~~
mousetrap.cpp:40:9: note: in expansion of macro 'fou'
   40 |         fou(task2);
      |         ^~~
mousetrap.cpp:13:23: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 | #define fin(x) freopen(x".inp","r",stdin)
      |                ~~~~~~~^~~~~~~~~~~~~~~~~~~
mousetrap.cpp:45:9: note: in expansion of macro 'fin'
   45 |         fin(task);
      |         ^~~
mousetrap.cpp:14:23: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 | #define fou(x) freopen(x".out","w",stdout)
      |                ~~~~~~~^~~~~~~~~~~~~~~~~~~~
mousetrap.cpp:46:9: note: in expansion of macro 'fou'
   46 |         fou(task);
      |         ^~~

• Subtask 1: 0 / 20
• Subtask 2: 0 / 25
• Subtask 3: 0 / 20
• Subtask 4: 0 / 35