Submission #935245

#	Time	Username	Problem	Language	Result	Execution time	Memory
935245		irmuun	Plus Minus (BOI17_plusminus)	C++17	100 / 100	40 ms	7248 KiB

plusminus

#include<bits/stdc++.h>
 
using namespace std;
 
#define ll long long
#define pb push_back
#define ff first
#define ss second
#define all(s) s.begin(),s.end()
#define rall(s) s.rbegin(),s.rend()

const ll mod=1e9+7;

ll binpow(ll a,ll b){
    ll res=1;
    while(b){
        if(b&1){
            res=res*a%mod;
        }
        a=a*a%mod;
        b=b>>1;
    }
    return res;
}

int main(){
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    ll n,m,k;
    cin>>n>>m>>k;
    vector<array<ll,3>>a(k),b(k);
    for(ll i=0;i<k;i++){
        char c;
        ll x,y;
        cin>>c>>x>>y;
        ll u=(c=='+');
        a[i]={x,y,u};
        b[i]={y,x,u};
    }
    sort(all(a));
    sort(all(b));
    ll ans=0;
    ll r=0,leftR=n,leftC=m;
    ll c[2][2];
    bool ok=true;
    for(ll i=0;i<k;){
        memset(c,0,sizeof c);
        c[a[i][2]][a[i][1]%2]++;
        r=i;
        while(r<k-1&&a[r+1][0]==a[r][0]){
            r++;
            c[a[r][2]][a[r][1]%2]++;
        }
        if(c[0][0]+c[1][1]==0){
            leftR--;
        }
        else if(c[1][0]+c[0][1]==0){
            leftR--;
        }
        else{
            ok=false;
        }
        i=r+1;
    }
    if(ok) ans=binpow(2,leftR);
    ok=true;
    for(ll i=0;i<k;){
        memset(c,0,sizeof c);
        c[b[i][2]][b[i][1]%2]++;
        r=i;
        while(r<k-1&&b[r+1][0]==b[r][0]){
            r++;
            c[b[r][2]][b[r][1]%2]++;
        }
        if(c[0][0]+c[1][1]==0){
            leftC--;
        }
        else if(c[1][0]+c[0][1]==0){
            leftC--;
        }
        else{
            ok=false;
        }
        i=r+1;
    }
    if(ok) ans=(ans+binpow(2,leftC))%mod;
    memset(c,0,sizeof c);
    for(ll i=0;i<k;i++){
        c[a[i][2]][(a[i][0]+a[i][1])%2]++;
    }
    if(c[0][0]+c[1][1]==0){
        ans--;
    }
    if(c[0][1]+c[1][0]==0){
        ans--;
    }
    if(ans<0) ans+=mod;
    cout<<ans;
}

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