Submission #1087346

#	Time	Username	Problem	Language	Result	Execution time	Memory
1087346		anhthi	Furniture (JOI20_furniture)	C++14	100 / 100	206 ms	16984 KiB

furniture

#include <bits/stdc++.h>

using namespace std;


#define fi first
#define se second
#define ll long long
#define mp(x, y) make_pair(x, y)
#define sz(v) ((int) (v).size())
#define all(v) (v).begin(), (v).end()
#define MASK(i) (1LL << (i))
#define BIT(x, y) (((x) >> (y)) & 1)
#define pb push_back
#define max_rng *max_element
#define min_rng *min_element
#define rep(i, n) for(int i = 1, _n = (n); i <= _n; ++i)
#define forn(i, a, b) for(int i = (a), _b = (b); i <= _b; ++i)
#define ford(i, a, b) for(int i = (a), _b = (b); i >= _b; --i)

template <class X, class Y>
    inline bool maximize(X &x, Y y) {
        return (x < y ? x = y, true : false);
    }

template <class X, class Y>
    inline bool minimize(X &x, Y y) {
        return (x > y ? x = y, true : false);
    }

template <class X>
    inline void compress(vector<X> &a) {
        sort(all(a));
        a.resize(unique(all(a)) - a.begin());
    }

int ctz(ll x) { return __builtin_ctzll(x); }
int lg(ll x) { return 63 - __builtin_clzll(x); }
int popcount(ll x) { return __builtin_popcount(x); }

mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rand(ll l, ll r) {
    return l + abs((ll) rng()) % (r - l + 1);
}

const ll oo = (ll) 1e17;
const int inf = (ll) 2e9 + 7, mod = (ll) 1e9 + 7;

const int mxn = 1e3 + 5;
const int LG = 18, BASE = 311;

void add(int &x, int y) { x += y; if (x >= mod) x -= mod; }
void sub(int &x, int y) { x -= y; if (x < 0) x += mod; }

int n, m, q;
int a[mxn][mxn];

bool ok[mxn][mxn];
int sum[mxn << 1 + 5];

int dx[] = {0, 0, -1, 1};
int dy[] = {-1, 1, 0, 0};

void backtrack(int i, int j) {
    if (ok[i][j]) return;

    sum[i+j]--;
    ok[i][j] = true;

    if (ok[i+1][j-1]) {
        backtrack(i+1, j);
        backtrack(i, j-1);
    }
    if (ok[i-1][j+1]) {
        backtrack(i, j+1);
        backtrack(i-1, j);
    }

    return;
}

int main(void) {

    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    #define TASK "task"
    if (fopen(TASK".inp", "r")) {
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }

    cin >> n >> m;
    rep(i, n) rep(j, m) cin >> a[i][j];

    rep(i, n) ok[i][0] = ok[i][m+1] = 1;
    rep(i, m) ok[0][i] = ok[n+1][i] = 1;

    rep(i, n) rep(j, m) sum[i + j]++;
    rep(i, n) rep(j, m) if (a[i][j]) {
        backtrack(i, j);
    }
    cin >> q;
    rep(_, q) {

        int x, y;
        cin >> x >> y;

        if (ok[x][y]) {
            cout << 1 << '\n';
        }
        else {
            if (sum[x + y] > 1) {
                cout << 1 << '\n';
                backtrack(x, y);
            }
            else {
                cout << 0 << '\n';
            }
        }
    }

    return 0;
}

Compilation message (stderr)

furniture.cpp:59:18: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
   59 | int sum[mxn << 1 + 5];
      |                ~~^~~
furniture.cpp: In function 'int main()':
furniture.cpp:89:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
furniture.cpp:90:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 95 / 95