oj.uz

Submission #567090

# Submission time Handle Problem Language Result Execution time Memory
567090 2022-05-23T07:56:55 Z azberjibiou Star Trek (CEOI20_startrek) C++17
38 / 100
 111 ms 13968 KB 
#include <bits/stdc++.h>
#define gibon ios::sync_with_stdio(false); cin.tie(0);
#define fir first
#define sec second
#define pdd pair<long double, long double>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define ld long double
#define pmax pair<__int128, __int128>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
typedef long long ll;
using namespace std;
int dx[4]= {0, 1, 0, -1}, dy[4]= {1, 0, -1, 0};
int ddx[8]={1, 1, 0, -1, -1, -1, 0, 1}, ddy[8]={0, 1, 1, 1, 0, -1, -1, -1};
const int mxN=100025;
const int mxM=300005;
const int mxK=1000000000;
const ll MOD=1000'000'007;
const ll INF=1000000000000000005;
ll N, D;
vector <int> v[mxN];
int outw[mxN];
int downw[mxN], upw[mxN];
bool W[mxN];
ll degL[mxN];
ll leafw2[mxN], sizl2[mxN], par2[mxN];
ll numw;
int match[mxN];
ll swapL1[mxN];
void dfs_downw(int now, int pre)
{
    for(int nxt : v[now])   if(nxt!=pre)
    {
        dfs_downw(nxt, now);
    }
    downw[now]=(outw[now]==0 ? 1 : 0);
    if(now!=1)  outw[pre]+=downw[now];
}
void dfs_upw(int now, int pre)
{
    if(now!=1)
    {
        upw[now]=(outw[pre]-downw[now]==0 ? 1 : 0);
        outw[now]+=upw[now];
    }
    for(int nxt : v[now])   if(nxt!=pre)
    {
        dfs_upw(nxt, now);
    }
}
int findpar(int a)
{
    return (par2[a]==a ? a : par2[a]=findpar(par2[a]));
}
void onion(int a, int b)
{
    int p=findpar(a), q=findpar(b);
    par2[p]=q;  sizl2[q]+=sizl2[p]; leafw2[q]+=leafw2[p];
}
int dfs_match(int now, int pre)
{
    for(int nxt : v[now])   if(nxt!=pre && W[nxt] && degL[nxt]==0)
    {
        int tmp=dfs_match(nxt, now);
        if(tmp!=0)  match[now]=tmp, match[tmp]=now;
    }
    if(match[now])  return 0;
    else    return now;
}
int dfs_swap(int now)
{
    if(swapL1[now]!=0)  return swapL1[now];
    ll sum=1;
    for(int nxt : v[match[now]])    if(nxt!=now && W[nxt] && degL[nxt]==0)
    {
        sum+=dfs_swap(nxt);
    }
    return swapL1[now]=sum;
}
ll f(ll a)
{
    return (a%MOD+MOD)%MOD;
}
ll mypow(ll a, ll b)
{
    if(b==0)    return 1;
    if(b==1)    return f(a);
    ll tmp=mypow(a, b/2);
    tmp*=tmp;   tmp%=MOD;
    if(b%2) tmp*=a; tmp%=MOD;
    return tmp;
}
int main()
{
    gibon
    cin >> N >> D;
    for(int i=1;i<N;i++)
    {
        int a, b;   cin >> a >> b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    dfs_downw(1, -1);
    dfs_upw(1, -1);
    for(int i=1;i<=N;i++)
    {
        W[i]=(outw[i]>=1);
        numw+=W[i];
    }
    for(int i=1;i<=N;i++)   for(int ele : v[i]) if(!W[ele]) degL[i]++;
    for(int i=1;i<=N;i++)
    {
        par2[i]=i;
        if(degL[i]==1) leafw2[i]=1;
        if(!W[i])   sizl2[i]=1;
    }
    for(int i=1;i<=N;i++)   for(int ele : v[i]) if(degL[ele]<3 && !W[i]) onion(i, ele);
    for(int i=1;i<=N;i++)   if(W[i] && degL[i]==0 && match[i]==0)   dfs_match(i, -1);
    for(int i=1;i<=N;i++)   if(W[i] && degL[i]==0)  dfs_swap(i);
    ll k1=numw, k2=0;
    for(int i=1;i<=N;i++)   k2-=swapL1[i];  k2=f(k2);
    for(int i=1;i<=N;i++)   if(findpar(i)==i)   k2+=sizl2[i]*(sizl2[i]-leafw2[i]), k2=f(k2);
    ll recur;
    if(D==1)    recur=numw;
    else    recur=(N*N%MOD*k1%MOD+N*k2%MOD)%MOD*(mypow(N, 2*(D-1))+mypow(f(k2), D-1))%MOD*mypow(f(N*N+k2), MOD-2)%MOD+mypow(MOD-1, D-1)*numw%MOD*mypow(k2, D-1)%MOD;
    recur=f(recur);
    ll powN=mypow(N, 2*D-1);
    if(W[1])
    {
        ll ans=powN*N%MOD;
        if(degL[1]==0)  ans-=(powN-recur)*swapL1[1]; ans=f(ans);
        if(degL[1]==1)  ans-=(powN-recur)*sizl2[findpar(1)]; ans=f(ans);
        cout << ans;
    }
    else
    {
        ll ans=0;
        ans+=(powN-recur)*sizl2[findpar(1)];
        cout << f(ans);
    }
}

Compilation message

startrek.cpp: In function 'll mypow(ll, ll)':
startrek.cpp:92:5: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   92 |     if(b%2) tmp*=a; tmp%=MOD;
      |     ^~
startrek.cpp:92:21: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   92 |     if(b%2) tmp*=a; tmp%=MOD;
      |                     ^~~
startrek.cpp: In function 'int main()':
startrek.cpp:123:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  123 |     for(int i=1;i<=N;i++)   k2-=swapL1[i];  k2=f(k2);
      |     ^~~
startrek.cpp:123:45: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
  123 |     for(int i=1;i<=N;i++)   k2-=swapL1[i];  k2=f(k2);
      |                                             ^~
startrek.cpp:133:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  133 |         if(degL[1]==0)  ans-=(powN-recur)*swapL1[1]; ans=f(ans);
      |         ^~
startrek.cpp:133:54: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  133 |         if(degL[1]==0)  ans-=(powN-recur)*swapL1[1]; ans=f(ans);
      |                                                      ^~~
startrek.cpp:134:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  134 |         if(degL[1]==1)  ans-=(powN-recur)*sizl2[findpar(1)]; ans=f(ans);
      |         ^~
startrek.cpp:134:62: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  134 |         if(degL[1]==1)  ans-=(powN-recur)*sizl2[findpar(1)]; ans=f(ans);
      |                                                              ^~~

Subtask #1
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 2 ms 2772 KB Output is correct

Subtask #2
0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Incorrect 2 ms 2644 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #3
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 3 ms 2644 KB Output is correct
3 Correct 1 ms 2644 KB Output is correct
4 Correct 3 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 2 ms 2656 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 3 ms 2644 KB Output is correct
3 Correct 1 ms 2644 KB Output is correct
4 Correct 3 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 2 ms 2656 KB Output is correct
7 Correct 2 ms 2772 KB Output is correct
8 Correct 2 ms 2772 KB Output is correct
9 Correct 2 ms 2772 KB Output is correct
10 Correct 2 ms 2772 KB Output is correct
11 Correct 3 ms 2812 KB Output is correct

Subtask #5
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 3 ms 2644 KB Output is correct
3 Correct 1 ms 2644 KB Output is correct
4 Correct 3 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 2 ms 2656 KB Output is correct
7 Correct 2 ms 2772 KB Output is correct
8 Correct 2 ms 2772 KB Output is correct
9 Correct 2 ms 2772 KB Output is correct
10 Correct 2 ms 2772 KB Output is correct
11 Correct 3 ms 2812 KB Output is correct
12 Correct 111 ms 13968 KB Output is correct
13 Correct 89 ms 13768 KB Output is correct
14 Correct 49 ms 11112 KB Output is correct
15 Correct 98 ms 12300 KB Output is correct
16 Correct 77 ms 12108 KB Output is correct

Subtask #6
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 3 ms 2644 KB Output is correct
3 Correct 1 ms 2644 KB Output is correct
4 Correct 3 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 2 ms 2656 KB Output is correct
7 Correct 2 ms 2772 KB Output is correct
8 Correct 2 ms 2772 KB Output is correct
9 Correct 2 ms 2772 KB Output is correct
10 Correct 2 ms 2772 KB Output is correct
11 Correct 3 ms 2812 KB Output is correct
12 Correct 2 ms 2644 KB Output is correct
13 Correct 2 ms 2772 KB Output is correct
14 Correct 2 ms 2644 KB Output is correct
15 Incorrect 2 ms 2644 KB Output isn't correct
16 Halted 0 ms 0 KB -

Subtask #7
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 3 ms 2644 KB Output is correct
3 Correct 1 ms 2644 KB Output is correct
4 Correct 3 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 2 ms 2656 KB Output is correct
7 Correct 2 ms 2772 KB Output is correct
8 Correct 2 ms 2772 KB Output is correct
9 Correct 2 ms 2772 KB Output is correct
10 Correct 2 ms 2772 KB Output is correct
11 Correct 3 ms 2812 KB Output is correct
12 Correct 111 ms 13968 KB Output is correct
13 Correct 89 ms 13768 KB Output is correct
14 Correct 49 ms 11112 KB Output is correct
15 Correct 98 ms 12300 KB Output is correct
16 Correct 77 ms 12108 KB Output is correct
17 Correct 2 ms 2644 KB Output is correct
18 Correct 2 ms 2772 KB Output is correct
19 Correct 2 ms 2644 KB Output is correct
20 Incorrect 2 ms 2644 KB Output isn't correct
21 Halted 0 ms 0 KB -

Subtask #8
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 2 ms 2772 KB Output is correct
3 Correct 2 ms 2644 KB Output is correct
4 Incorrect 2 ms 2644 KB Output isn't correct
5 Halted 0 ms 0 KB -