Submission #719865

#	Time	Username	Problem	Language	Result	Execution time	Memory
719865		n0sk1ll	Plus Minus (BOI17_plusminus)	C++17	100 / 100	140 ms	13288 KiB

plusminus

#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

#define int li

int power(int a, int n)
{
    li c=1;
    while (n)
    {
        if (n&1) (c*=a)%=mod;
        a=(li)a*a%mod,n>>=1;
    }
    return c;
}

bool nemozerow=false;
bool nemozecol=false;
map<int,bool> row;
map<int,bool> col;

int odg=0;
int matra[7][7];

void rekurz(int i, int j, int n, int m)
{
    if (j>m) j=1,i++;

    if (i>n)
    {
        odg++;
        /*cout<<"mogucnost:"<<endl;
        fff(i,1,n)
        {
            fff(j,1,m) cout<<matra[i][j]<<" ";
            cout<<endl;
        } cout<<endl;*/
    }
    else if (i==1 || j==1)
    {
        if (!matra[i][j])
        {
            matra[i][j]=1;
            rekurz(i,j+1,n,m);
            matra[i][j]=-1;
            rekurz(i,j+1,n,m);
            matra[i][j]=0;
        }
        else rekurz(i,j+1,n,m);
    }
    else
    {
        if (matra[i][j])
        {
            if (matra[i][j]+matra[i-1][j]+matra[i][j-1]+matra[i-1][j-1]!=0) return;
            rekurz(i,j+1,n,m);
        }
        else
        {
            if (matra[i-1][j]+matra[i][j-1]+matra[i-1][j-1]+1==0) matra[i][j]=1,rekurz(i,j+1,n,m),matra[i][j]=0;
            if (matra[i-1][j]+matra[i][j-1]+matra[i-1][j-1]-1==0) matra[i][j]=-1,rekurz(i,j+1,n,m),matra[i][j]=0;
        }
    }
}

int solve()
{
    int n,m,k; cin>>n>>m>>k;
    bool edgecase=(k==0);
    while (k--)
    {
        char signe;
        int y,x; cin>>signe>>y>>x;
        bool booligne=(signe=='+')^(y&1)^(x&1);
        if (row.count(y) && booligne!=row[y]) nemozerow=true;
        if (col.count(x) && booligne!=col[x]) nemozecol=true;
        row[y]=booligne,col[x]=booligne;
    }

    if (nemozerow && nemozecol) return 0;

    int ans=0;
    if (!nemozerow)
    {
        (ans+=power(2,n-(int)row.size()))%=mod;
        bool isparan=false,isneparan=false;
        for (auto it : row) if (it.yy) isparan=true; else isneparan=true;
        if (!isparan || !isneparan) ans--;
    }
    if (!nemozecol)
    {
        (ans+=power(2,m-(int)col.size()))%=mod;
    }

    if (edgecase) ans--;
    return ans;
}

int solvebrute()
{
    int n,m,k; cin>>n>>m>>k;
    if (n>5 || m>5) return 0;

    while (k--)
    {
        char signe;
        int y,x; cin>>signe>>y>>x;
        matra[y][x]=(signe=='+'?1:-1);
    }

    rekurz(1,1,n,m);
    return odg;
}

signed main()
{
    FAST;

    cout<<solve()<<"\n";

    /*fff(T,1,1000)
    {
        nemozerow=false;
        nemozecol=false;
        row.clear();
        col.clear();

        odg=0;
        fff(i,0,6) fff(j,0,6) matra[i][j]=0;

        int ocevidnolos=solve();
        int dobar=solvebrute();
        cout<<": "<<ocevidnolos<<" "<<dobar<<endl<<endl;
        if (dobar!=ocevidnolos) cout<<"FATAL ERROR ==============================="<<endl<<endl<<"FATAL ERROR ==============================="<<endl<<endl<<"FATAL ERROR ==============================="<<endl<<endl<<"FATAL ERROR ==============================="<<endl<<endl<<"FATAL ERROR ==============================="<<endl<<endl<<endl;
    }*/
}

//Note to self: Check for overflow

/*

5 5 2
- 5 1
+ 5 5

4 4 3
- 4 1
+ 4 4
+ 3 4

2 2 4
+ 1 1
+ 2 2
- 1 2
- 2 1

*/

• Subtask 1: 12 / 12
• Subtask 2: 42 / 42
• Subtask 3: 46 / 46