Submission #1097502

#	Time	Username	Problem	Language	Result	Execution time	Memory
1097502		modwwe	The Xana coup (BOI21_xanadu)	C++17	0 / 100	2 ms	604 KiB

xanadu

//https://www.instagram.com/_modwwe/
#pragma GCC optimize("Ofast,unroll-loops")
//#pragma GCC target("avx2,bmi,bmi2")
#include<bits/stdc++.h>
//#define int long long
//#define ll long long
#define down cout<<'\n';
#define debug cout<<" cucuucucuuu",down
#define NHP     ios_base::sync_with_stdio(0);cout.tie(0);cin.tie(0);
#define modwwe  int t;cin>>t; while(t--)
#define bit(i,j) (i>>j&1)
#define sobit(a) __builtin_popcountll(a)
#define task "test"
#define fin(x) freopen(x".inp","r",stdin)
#define fou(x) freopen(x".out ","w",stdout)
#define pb push_back
#define vii vector<pii>
#define checktime   cerr << (double)clock() / CLOCKS_PER_SEC * 1000  << " ms";
using namespace std;
void phongbeo();
const int inf=1e9;
const int mod2=1e9+7;
const int  mod1=998244353;
struct icd
{
    int a,b;
    string c;
};
struct ib
{
    int a;
    int b;
};
struct ic
{
    int a,b,c;
};
struct id
{
    int a,b,c,d;
};
struct ie
{
    int a,b,c, d,e;

};
int n,m,s1,s2,s4,s3,sf,k,r,mid,s5,s6,mx,s7,s8,s9,mx2,res,dem2=0,l,l2,r2,dem=0;
int  i,s10,s12;
int el=29;
main()
{
#ifndef ONLINE_JUDGE
    fin(task);
    fou(task);
#endif
    NHP
    /// cin>>s1;
///    modwwe
    phongbeo(),down
}
int dp[3001][2][2];
vector<int> v[3001];
id trace[1001][1001][2][2];
ie trace2[1001][1001][2][2];
int b[3001];
bool c[3001];
int a[3001];
bool de=0;
void dfs(int x,int y)
{
    /// 0 0 no tat cac con no tat
    /// 0 1 no tat cac con no bat
    /// 1 0 no bat cac con no tat
    /// 1 1 no va cac con bat
    dp[x][b[x]][1]=0;
    dp[x][1-b[x]][1]=inf;
    dp[x][1-b[x]][0]=inf;
    dp[x][b[x]][0]=0;
    int ss=0;
    for(auto f:v[x])
    {
        ss++;
        if(f!=y)
        {
            dfs(f,x);
            s2=dp[x][0][0];
            s3=dp[x][0][1];
            s4=dp[x][1][0];
            s5=dp[x][1][1];
            dp[x][0][0]=dp[x][0][0]+dp[f][0][0];
            dp[x][1][0]=dp[x][1][0]+dp[f][0][0];
            dp[x][0][1]=dp[x][0][1]+dp[f][1][0];
            dp[x][1][1]=dp[x][1][1]+dp[f][1][0];
            if(!c[f])
            {
                dp[x][0][0]=min({dp[x][0][0],s4+dp[f][1][1]+1});
                dp[x][1][0]=min({dp[x][1][0],s2+dp[f][1][1]+1});
                dp[x][0][1]=min({dp[x][0][1],s5+dp[f][0][1]+1});
                dp[x][1][1]=min({dp[x][1][1],s3+dp[f][0][1]+1});
            }
            /// dpx00
            {
                if(dp[x][0][0]==s2+dp[f][0][0])
                {
                    trace[ss][x][0][0]= {ss-1,x,0,0};
                    trace2[ss][x][0][0]= {v[f].size(),f,0,0,0};
                }
                else if(dp[x][0][0]==s4+dp[f][1][1]+1)
                {
                    trace[ss][x][0][0]= {ss-1,x,1,0};
                    trace2[ss][x][0][0]= {v[f].size(),f,1,1,1};
                }
            }
            ///dpx10
            {
                if(dp[x][1][0]==s4+dp[f][0][0])
                {
                    trace[ss][x][1][0]= {ss-1,x,1,0};
                    trace2[ss][x][1][0]= {v[f].size(),f,0,0,0};
                }
                else if(dp[x][1][0]==s2+dp[f][1][1]+1)
                {
                    trace[ss][x][1][0]= {ss-1,x,0,0};
                    trace2[ss][x][1][0]= {v[f].size(),f,1,1,1};
                }
            }
            ///dpx01
            {
                if(dp[x][0][1]==s3+dp[f][1][0])
                {
                    trace[ss][x][0][1]= {ss-1,x,0,1};
                    trace2[ss][x][0][1]= {v[f].size(),f,1,0,0};
                }
                else if(dp[x][0][1]==s5+dp[f][0][1]+1)
                {
                    trace[ss][x][0][1]= {ss-1,x,1,1};
                    trace2[ss][x][0][1]= {v[f].size(),f,0,1,1};

                }
            }
            /// dpx11
            {

                if(dp[x][1][1]==s5+dp[f][1][0])
                {
                    trace[ss][x][1][1]= {ss-1,x,1,1};
                    trace2[ss][x][1][1]= {v[f].size(),f,1,0,0};
                }
                else if(dp[x][1][1]==s3+dp[f][0][1]+1)
                {
                    trace[ss][x][1][1]= {ss-1,x,0,1};
                    trace2[ss][x][1][1]= {v[f].size(),f,0,1,1};
                }
            }
        }
    }
}
vector<int> vans;
void backtrack(int x,int y,int z,int f)
{
    if(trace[x][y][z][f].b!=0)
    backtrack(trace[x][y][z][f].a,trace[x][y][z][f].b,trace[x][y][z][f].c,trace[x][y][z][f].d);
    if(trace2[x][y][z][f].e) vans.pb(trace2[x][y][z][f].b);
    if(trace2[x][y][z][f].b!=0)
    backtrack(trace2[x][y][z][f].a,trace2[x][y][z][f].b,trace2[x][y][z][f].c,trace2[x][y][z][f].d);
}
void case1()
{
/// no swap
    for(int i=1; i<=n; i++)
        b[i]=a[i];
//   for(auto x:v[l])
//   b[x]=1-b[x];
    //  for(auto x:v[r])
    //     b[x]=1-b[x];
    dfs(1,0);
     if(dp[1][0][0]<inf)
    {de=1;
        backtrack(v[1].size(),1,0,0);
    }
    else  if(dp[1][1][1]<inf&&!c[1])
    {de=1;
     vans.pb(1);
        backtrack(v[1].size(),1,1,1);
    }
}
void case2()
{
/// swap left
    for(int i=1; i<=n; i++)
        b[i]=a[i];
    for(auto x:v[l])
        b[x]=1-b[x];
    b[l]=1-b[l];
    //  for(auto x:v[r])
    //     b[x]=1-b[x];
    dfs(1,0);
    if(dp[1][0][0]<=inf)
    {de=1;
        vans.pb(l);
        backtrack(v[1].size(),1,0,0);
    }
    else  if(dp[1][1][1]<=inf&&!c[1])
    {de=1;
        vans.pb(l);
             vans.pb(1);

        backtrack(v[1].size(),1,1,1);
    }
}
void case3()
{
/// swap right
    for(int i=1; i<=n; i++)
        b[i]=a[i];
    // for(auto x:v[l])
//   b[x]=1-b[x];
///b[l]=1-b[l];
    for(auto x:v[r])
        b[x]=1-b[x];
    b[r]=1-b[r];
    dfs(1,0);
    if(dp[1][0][0]<=inf)
    {de=1;
        vans.pb(r);
        backtrack(v[1].size(),1,0,0);
    }
    else  if(dp[1][1][1]<=inf&&!c[1])
    {de=1;
         vans.pb(1);

        vans.pb(r);
        backtrack(v[1].size(),1,1,1);
    }
}
void case4()
{
/// no swap
    for(int i=1; i<=n; i++)
        b[i]=a[i];
    for(auto x:v[l])
        b[x]=1-b[x];
    b[l]=1-b[l];
    for(auto x:v[r])
        b[x]=1-b[x];
    b[r]=1-b[r];

    dfs(1,0);
    if(dp[1][0][0]<=inf)
    {de=1;
        vans.pb(l);
        vans.pb(r);
        backtrack(v[1].size(),1,0,0);
    }
    else  if(dp[1][1][1]<=inf&&!c[1])
    {de=1;
        vans.pb(l);
        vans.pb(r);
             vans.pb(1);
        backtrack(v[1].size(),1,1,1);
    }
}

void phongbeo()
{
    cin>>n;
    m=1;
    for(int i=1; i<n; i++)
        cin>>l>>r,v[l].pb({r}),
            v[r].pb({l});
//    cin>>l>>r;
 //   c[l]=1;
  //  c[r]=1;
    for(int i=1; i<=m; i++)
    {
        for(int i=1; i<=n; i++)
            cin>>a[i];
            vans.clear();
        de=0;
        case1();
        //if(!de)case2();
        //if(!de) case3();
        //if(!de)case4();
        if(!de) cout<<"impossible",down
                        else
            {
                cout<<vans.size();
                //<<" ";
              //  for(auto x:vans)
               //     cout<<x<<" ";
                //down
            }
    }
}

Compilation message (stderr)

xanadu.cpp:50:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   50 | main()
      | ^~~~
xanadu.cpp: In function 'void dfs(int, int)':
xanadu.cpp:106:52: warning: narrowing conversion of 'v[f].std::vector<int>::size()' from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' [-Wnarrowing]
  106 |                     trace2[ss][x][0][0]= {v[f].size(),f,0,0,0};
      |                                           ~~~~~~~~~^~
xanadu.cpp:111:52: warning: narrowing conversion of 'v[f].std::vector<int>::size()' from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' [-Wnarrowing]
  111 |                     trace2[ss][x][0][0]= {v[f].size(),f,1,1,1};
      |                                           ~~~~~~~~~^~
xanadu.cpp:119:52: warning: narrowing conversion of 'v[f].std::vector<int>::size()' from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' [-Wnarrowing]
  119 |                     trace2[ss][x][1][0]= {v[f].size(),f,0,0,0};
      |                                           ~~~~~~~~~^~
xanadu.cpp:124:52: warning: narrowing conversion of 'v[f].std::vector<int>::size()' from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' [-Wnarrowing]
  124 |                     trace2[ss][x][1][0]= {v[f].size(),f,1,1,1};
      |                                           ~~~~~~~~~^~
xanadu.cpp:132:52: warning: narrowing conversion of 'v[f].std::vector<int>::size()' from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' [-Wnarrowing]
  132 |                     trace2[ss][x][0][1]= {v[f].size(),f,1,0,0};
      |                                           ~~~~~~~~~^~
xanadu.cpp:137:52: warning: narrowing conversion of 'v[f].std::vector<int>::size()' from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' [-Wnarrowing]
  137 |                     trace2[ss][x][0][1]= {v[f].size(),f,0,1,1};
      |                                           ~~~~~~~~~^~
xanadu.cpp:147:52: warning: narrowing conversion of 'v[f].std::vector<int>::size()' from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' [-Wnarrowing]
  147 |                     trace2[ss][x][1][1]= {v[f].size(),f,1,0,0};
      |                                           ~~~~~~~~~^~
xanadu.cpp:152:52: warning: narrowing conversion of 'v[f].std::vector<int>::size()' from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' [-Wnarrowing]
  152 |                     trace2[ss][x][1][1]= {v[f].size(),f,0,1,1};
      |                                           ~~~~~~~~~^~
xanadu.cpp: In function 'void phongbeo()':
xanadu.cpp:276:9: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  276 |         for(int i=1; i<=n; i++)
      |         ^~~
xanadu.cpp:278:13: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
  278 |             vans.clear();
      |             ^~~~
xanadu.cpp: In function 'int main()':
xanadu.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 fin(x) freopen(x".inp","r",stdin)
      |                ~~~~~~~^~~~~~~~~~~~~~~~~~~
xanadu.cpp:53:5: note: in expansion of macro 'fin'
   53 |     fin(task);
      |     ^~~
xanadu.cpp:15:23: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 | #define fou(x) freopen(x".out ","w",stdout)
      |                ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
xanadu.cpp:54:5: note: in expansion of macro 'fou'
   54 |     fou(task);
      |     ^~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 15
• Subtask 3: 0 / 10
• Subtask 4: 0 / 40
• Subtask 5: 0 / 30