結果
| 問題 | 
                            No.697 池の数はいくつか
                             | 
                    
| ユーザー | 
                             | 
                    
| 提出日時 | 2023-01-06 12:23:11 | 
| 言語 | C++17  (gcc 13.3.0 + boost 1.87.0)  | 
                    
| 結果 | 
                             
                                AC
                                 
                             
                            
                         | 
                    
| 実行時間 | 892 ms / 6,000 ms | 
| コード長 | 4,020 bytes | 
| コンパイル時間 | 5,743 ms | 
| コンパイル使用メモリ | 255,880 KB | 
| 最終ジャッジ日時 | 2025-02-09 23:27:44 | 
| 
                            ジャッジサーバーID (参考情報)  | 
                        judge3 / judge3 | 
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| ファイルパターン | 結果 | 
|---|---|
| sample | AC * 3 | 
| other | AC * 32 | 
ソースコード
#pragma region Macros
#include <bits/extc++.h>
using namespace std;
using namespace __gnu_pbds;
// using namespace __gnu_cxx;
// #include <boost/multiprecision/cpp_int.hpp>
// namespace mp = boost::multiprecision;
// using Bint = mp::cpp_int;
#define TO_STRING(var) # var
#define pb emplace_back
#define int ll
#define endl '\n'
using ll = long long;
using ld = long double;
const ld PI = acos(-1);
const ld EPS = 1e-10;
const int INF = 1 << 30;
const ll INFL = 1LL << 61;
// const int MOD = 998244353;
const int MOD = 1000000007;
__attribute__((constructor))
void constructor() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    // ifstream in("input.txt");
    // cin.rdbuf(in.rdbuf());
    cout << fixed << setprecision(15);
}
template<int mod> class modint{
public:
    int val = 0;
    modint(int x = 0) { while (x < 0) x += mod; val = x % mod; }
    modint(const modint &r) { val = r.val; }
    modint operator -() { return modint(-val); }
    modint operator +(const modint &r) { return modint(*this) += r; }
    modint operator -(const modint &r) { return modint(*this) -= r; }
    modint operator *(const modint &r) { return modint(*this) *= r; }
    modint operator /(const modint &r) { return modint(*this) /= r; }
    modint &operator +=(const modint &r) {
        val += r.val;
        if (val >= mod) val -= mod;
        return *this;
    }
    modint &operator -=(const modint &r) {
        if (val < r.val) val += mod;
        val -= r.val;
        return *this;
    }
    modint &operator *=(const modint &r) {
        val = val * r.val % mod;
        return *this;
    }
    modint &operator /=(const modint &r) {
        int a = r.val, b = mod, u = 1, v = 0;
        while (b) {
            int t = a / b;
            a -= t * b; swap(a, b);
            u -= t * v; swap(u, v);
        }
        val = val * u % mod;
        if (val < 0) val += mod;
        return *this;
    }
    bool operator ==(const modint& r) { return this -> val == r.val; }
    bool operator <(const modint& r) { return this -> val < r.val; }
    bool operator !=(const modint& r) { return this -> val != r.val; }
};
using mint = modint<MOD>;
istream &operator >>(istream &is, mint& x) {
    int t; is >> t;
    x = t;
    return (is);
}
ostream &operator <<(ostream &os, const mint& x) {
    return os << x.val;
}
mint modpow(const mint &a, int n) {
    if (n == 0) return 1;
    mint t = modpow(a, n / 2);
    t = t * t;
    if (n & 1) t = t * a;
    return t;
}
int modpow(int x, int n, int mod) {
    int ret = 1;
    while (n > 0) {
        if (n % 2 == 1) ret = ret * x % mod;
        x = x * x % mod;
        n /= 2;
    }
    return ret;
}
int ceil(int x, int y) { return (x > 0 ? (x + y - 1) / y : x / y); }
#pragma endregion
const vector<int> dx = {1, 0, -1, 0};
const vector<int> dy = {0, -1, 0, 1};
int H, W;
bool isvalid(int x, int y) {
    if (x >= 0 && x < H && y >= 0 && y < W) return true;
    else return false;
}
signed main() {
    cin >> H >> W;
    vector<vector<int>> A(H, vector<int>(W));
    for (int i = 0; i < H; i++) {
        for (int j = 0; j < W; j++) {
            cin >> A[i][j];
        }
    }
    int ans = 0;
    for (int i = 0; i < H; i++) {
        for (int j = 0; j < W; j++) {
            if (A[i][j] == 1) {
                ans++;
                queue<pair<int,int>> qu;
                qu.emplace(i, j);
                A[i][j] = 0;
                while (!qu.empty()) {
                    int x = qu.front().first;
                    int y = qu.front().second;
                    qu.pop();
                    for (int k = 0; k < 4; k++) {
                        int nx = x + dx[k];
                        int ny = y + dy[k];
                        if (!isvalid(nx, ny)) continue;
                        if (A[nx][ny] == 1) {
                            qu.emplace(nx, ny);
                            A[nx][ny] = 0;
                        }
                    }
                }
            }
        }
    }
    cout << ans << endl;
}