結果
問題 | No.2456 Stamp Art |
ユーザー |
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提出日時 | 2023-09-01 22:46:08 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 276 ms / 5,000 ms |
コード長 | 3,783 bytes |
コンパイル時間 | 1,253 ms |
コンパイル使用メモリ | 122,968 KB |
最終ジャッジ日時 | 2025-02-16 17:05:14 |
ジャッジサーバーID (参考情報) |
judge1 / judge2 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 23 |
ソースコード
#include <iostream>#include <algorithm>#include <iomanip>#include <vector>#include <queue>#include <deque>#include <set>#include <map>#include <tuple>#include <cmath>#include <numeric>#include <functional>#include <cassert>#define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl;#define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl;template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }using namespace std;typedef long long ll;template<typename T>vector<vector<T>> vec2d(int n, int m, T v){return vector<vector<T>>(n, vector<T>(m, v));}template<typename T>vector<vector<vector<T>>> vec3d(int n, int m, int k, T v){return vector<vector<vector<T>>>(n, vector<vector<T>>(m, vector<T>(k, v)));}template<typename T>void print_vector(vector<T> v, char delimiter=' '){if(v.empty()) {cout << endl;return;}for(int i = 0; i+1 < v.size(); i++) cout << v[i] << delimiter;cout << v.back() << endl;}template<typename T>class CumsumGrid{public:CumsumGrid(vector<vector<T>> v): v(v){n = v.size();m = v[0].size();v_cumsum = vector<vector<T>>(n+1, vector<T>(m+1, T(0)));for(int i = 0; i < n; i++) {for(int j = 0; j < m; j++){v_cumsum[i+1][j+1] = v_cumsum[i+1][j]+v_cumsum[i][j+1]-v_cumsum[i][j]+v[i][j];}}}/*** sum(v[il:ir)[jl:jr))*/T sum(int il, int ir, int jl, int jr){if(ir <= il) return T(0);if(jr <= jl) return T(0);if(ir > n) ir = n;if(jr > m) jr = m;if(il < 0) il = 0;if(jl < 0) jl = 0;return v_cumsum[ir][jr]-v_cumsum[ir][jl]-v_cumsum[il][jr]+v_cumsum[il][jl];}private:int n, m;vector<vector<T>> v;vector<vector<T>> v_cumsum;};int imos[2005][2005];int main(){ios::sync_with_stdio(false);cin.tie(0);cout << setprecision(10) << fixed;int h, w; cin >> h >> w;vector<string> s(h);for(int i = 0; i < h; i++) cin >> s[i];auto c = vec2d(h, w, 0);for(int i = 0; i < h; i++){for(int j = 0; j < w; j++){if(s[i][j] == '.') c[i][j] = 1;}}auto cumsum = CumsumGrid<int>(c);auto clear = [&](){for(int i = 0; i <= h; i++){for(int j = 0; j <= w; j++){imos[i][j] = 0;}}};auto ok = [&](int len){clear();for(int i = 0; i+len <= h; i++){for(int j = 0; j+len <= w; j++){if(cumsum.sum(i, i+len, j, j+len) == 0){imos[i][j]++;imos[i+len][j]--;imos[i][j+len]--;imos[i+len][j+len]++;}}}for(int i = 0; i < h; i++){for(int j = 1; j <= w; j++){imos[i][j] += imos[i][j-1];}}for(int i = 1; i <= h; i++){for(int j = 0; j < w; j++){imos[i][j] += imos[i-1][j];}}for(int i = 0; i < h; i++) {for(int j = 0; j < w; j++){bool black = s[i][j] == '#';bool cur_black = imos[i][j] > 0;if(black != cur_black) return false;}}return true;};int l = 1, r = min(h, w);if(ok(r)){cout << r << endl;return 0;}while(r-l > 1){int len = (l+r)/2;if(ok(len)) l = len;else r = len;}cout << l << endl;}