Submission #365037

# Submission time Handle Problem Language Result Execution time Memory
365037 2021-02-10T19:50:18 Z giorgikob Furniture (JOI20_furniture) C++14
100 / 100
3845 ms 310420 KB
#include<bits/stdc++.h>
#define ll long long
#define ff first
#define ss second
#define pb push_back
using namespace std;

const int N = 1e3+5;

int n,m;
int A[N][N];
set<int>in[N*N],out[N*N];
int fix[N*N];
int x,a,b;
int H[N*N],cnt[N*N],can[N*N];

void erase_vertex(int x){
    //cout << x << " ----" << endl;
    for(auto to : out[x]){
        in[to].erase(x);//cout << x << " " << to << endl;
    }

    for(auto to : in[x]){
        out[to].erase(x); //cout << to << " " << x << endl;
    }
    //cout << "----" << endl;
}


void add_edge(int x,int y){
    out[x].insert(y); in[y].insert(x);
    out[x].insert(y); in[y].insert(x);
}

void dfs(int x,int h){
    //cout << x << endl;
    fix[x] = 1;
    H[x] = h;

    if(x == n*m){
        can[x] = 1;
        cnt[h]++;
        return ;
    }

    for(auto to : out[x]){
        if(fix[to] == 0)
        dfs(to,h+1);
        can[x] |= can[to];
    }

    cnt[h] += can[x];
}

bool check(int x){
    if(cnt[H[x]+1] > out[x].size()) return true;

    for(auto to : out[x]){
        if(in[to].size() == 2) return true;
    }

    return false;
}

void go_down(int x,int p){
    in[x].erase(p);
    if(in[x].size() == 1) return ;
    cnt[H[x]]--;
    can[x] = 0;
    for(auto to : out[x]){
        go_down(to,x);
    }
}

void go_up(int x,int p){
    out[x].erase(p);
    if(out[x].size() == 1) return ;
    cnt[H[x]]--;
    can[x] = 0;
    for(auto to : in[x]){
        go_up(to,x);
    }
}

int main(){

    cin >> n >> m;
    int a = 0;
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= m; j++){
            cin >> A[i][j];
         }
    }

    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= m; j++){
            a++;
            if(!A[i][j] && !A[i][j+1] && j+1 <= m)add_edge(a,a+1);
            if(!A[i][j] && !A[i+1][j] && i+1 <= n)add_edge(a,a+m);
         }
    }

    //cout << 1 << endl;
    dfs(1,0);

    for(int i = 1; i <= n*m; i++) if(can[i] == 0) erase_vertex(i);

    int q;
    cin >> q;
    while(q--){
        cin >> a >> b;
        x = (a-1)*m+b;
        if(can[x] == 0){
            cout << 1 << endl;
            continue;
        }


        if(check(x)){
            cout << 1 << endl;
            can[x] = 0; cnt[H[x]]--;
            for(auto to : out[x])go_down(to,x);
            for(auto to : in[x])go_up(to,x);
        } else {
            cout << 0 << endl;
        }
    }
}

Compilation message

furniture.cpp: In function 'bool check(int)':
furniture.cpp:56:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::set<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |     if(cnt[H[x]+1] > out[x].size()) return true;
      |        ~~~~~~~~~~~~^~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 66 ms 96620 KB Output is correct
2 Correct 71 ms 96236 KB Output is correct
3 Correct 75 ms 97004 KB Output is correct
4 Correct 92 ms 97132 KB Output is correct
5 Correct 90 ms 97260 KB Output is correct
6 Correct 94 ms 97772 KB Output is correct
7 Correct 93 ms 97772 KB Output is correct
8 Correct 94 ms 97772 KB Output is correct
9 Correct 96 ms 97900 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 66 ms 96620 KB Output is correct
2 Correct 71 ms 96236 KB Output is correct
3 Correct 75 ms 97004 KB Output is correct
4 Correct 92 ms 97132 KB Output is correct
5 Correct 90 ms 97260 KB Output is correct
6 Correct 94 ms 97772 KB Output is correct
7 Correct 93 ms 97772 KB Output is correct
8 Correct 94 ms 97772 KB Output is correct
9 Correct 96 ms 97900 KB Output is correct
10 Correct 160 ms 104684 KB Output is correct
11 Correct 82 ms 97260 KB Output is correct
12 Correct 1776 ms 271468 KB Output is correct
13 Correct 606 ms 236376 KB Output is correct
14 Correct 3178 ms 267300 KB Output is correct
15 Correct 3460 ms 277416 KB Output is correct
16 Correct 3377 ms 292996 KB Output is correct
17 Correct 3683 ms 303660 KB Output is correct
18 Correct 3753 ms 298348 KB Output is correct
19 Correct 3725 ms 310376 KB Output is correct
20 Correct 3845 ms 310292 KB Output is correct
21 Correct 3829 ms 310420 KB Output is correct