// #pragma GCC optimize("O3,unroll-loops") #include // #include using namespace std; #if __cplusplus >= 202002L using namespace numbers; #endif template struct segment_tree_base{ static_assert(HAS_QUERY || HAS_UPDATE); #ifdef LOCAL #define ASSERT(c) assert(c) #else #define ASSERT(c) 42 #endif #define ifQ if constexpr(HAS_QUERY) #define ifU if constexpr(HAS_UPDATE) int n, size, log; vector data; vector data_action; F1 TT; // monoid operation (always adjacent) T T_id; // monoid identity F2 UU; // monoid operation (superset, subset) U U_id; // monoid identity F3 UT; // action of U on T (superset, subset) // O(n) segment_tree_base(F1 TT, T T_id, F2 UU, U U_id, F3 UT): TT(TT), T_id(T_id), UU(UU), U_id(U_id), UT(UT){ } segment_tree_base &operator=(const segment_tree_base &seg){ n = seg.n; size = seg.size; log = seg.log; data = seg.data; data_action = seg.data_action; } // O(1) friend void swap(segment_tree_base &x, segment_tree_base &y){ swap(x.n, y.n); swap(x.size, y.size); swap(x.log, y.log); swap(x.data, y.data); swap(x.data_action, y.data_action); } // O(n) void build(int n){ ASSERT(n >= 0); this->n = n; size = 1; while(size < n) size <<= 1; log = __lg(size); ifQ data.assign(size << 1, T_id); ifU data_action.assign(HAS_QUERY ? size : size << 1, U_id); } // O(n) void build(int n, T x){ static_assert(HAS_QUERY); ASSERT(n >= 0); this->n = n; size = 1; while(size < n) size <<= 1; log = __lg(size); data.assign(size << 1, T_id); fill(data.begin() + size, data.begin() + size + n, x); for(auto i = size - 1; i >= 1; -- i) refresh(i); ifU data_action.assign(size, U_id); } // O(n) template void build(const vector &a){ static_assert(HAS_QUERY); n = (int)a.size(); size = 1; while(size < n) size <<= 1; log = __lg(size); data.assign(size << 1, T_id); copy(a.begin(), a.end(), data.begin() + size); for(auto i = size - 1; i >= 1; -- i) refresh(i); ifU data_action.assign(size, U_id); } // O(n) void build_action(int n){ static_assert(!HAS_QUERY && HAS_UPDATE); ASSERT(n >= 0); build(n); } // O(n) void build_action(int n, U f){ static_assert(!HAS_QUERY && HAS_UPDATE); ASSERT(n >= 0); this->n = n; size = 1; while(size < n) size <<= 1; log = __lg(size); data_action.assign(size << 1, U_id); fill(data_action.begin() + size, data_action.begin() + size + n, f); } // O(n) template void build_action(const vector &a){ static_assert(!HAS_QUERY && HAS_UPDATE); n = (int)a.size(); size = 1; while(size < n) size <<= 1; log = __lg(size); data_action.assign(size << 1, U_id); copy(a.begin(), a.end(), data_action.begin() + size); } // O(1) void refresh(int u){ static_assert(HAS_QUERY); data[u] = TT(data[u << 1], data[u << 1 | 1]); } // O(1) void apply(int u, U f){ static_assert(HAS_UPDATE); ifQ data[u] = UT(f, data[u]); if(!HAS_QUERY || u < size) data_action[u] = UU(f, data_action[u]); } // O(1) void push(int u){ static_assert(HAS_UPDATE); apply(u << 1, data_action[u]), apply(u << 1 | 1, data_action[u]); data_action[u] = U_id; } // O(log(n)) if HAS_UPDATE, O(1) otherwise. T query(int p){ static_assert(HAS_QUERY); ASSERT(0 <= p && p < n); p += size; ifU for(auto i = log; i >= 1; -- i) push(p >> i); return data[p]; } // O(log(n)) U query_action(int p){ static_assert(!HAS_QUERY && HAS_UPDATE); ASSERT(0 <= p && p < n); p += size; ifU for(auto i = log; i >= 1; -- i) push(p >> i); return data_action[p]; } // O(log(n)) T query(int ql, int qr){ static_assert(HAS_QUERY); ASSERT(0 <= ql && ql <= qr && qr <= n); if(ql == qr) return T_id; ql += size, qr += size; ifU for(auto i = log; i >= 1; -- i){ if(ql >> i << i != ql) push(ql >> i); if(qr >> i << i != qr) push(qr >> i); } T res_left = T_id, res_right = T_id; for(; ql < qr; ql >>= 1, qr >>= 1){ if(ql & 1) res_left = TT(res_left, data[ql ++]); if(qr & 1) res_right = TT(data[-- qr], res_right); } return TT(res_left, res_right); } // O(1) T query_all() const{ static_assert(HAS_QUERY); return data[1]; } // O(n) vector to_array(){ static_assert(HAS_QUERY); ifU for(auto u = 1; u < size; ++ u) push(u); return vector(data.begin() + size, data.begin() + size + n); } // O(n) vector to_array_of_updates(){ static_assert(!HAS_QUERY && HAS_UPDATE); for(auto u = 1; u < size; ++ u) push(u); return vector(data_action.begin() + size, data_action.begin() + size + n); } // O(log(n)) void set(int p, T x){ static_assert(HAS_QUERY); ASSERT(0 <= p && p < n); p += size; ifU for(auto i = log; i >= 1; -- i) push(p >> i); data[p] = x; for(auto i = 1; i <= log; ++ i) refresh(p >> i); } // O(log(n)) void set_action(int p, U f){ static_assert(!HAS_QUERY && HAS_UPDATE); ASSERT(0 <= p && p < n); p += size; for(auto i = log; i >= 1; -- i) push(p >> i); data_action[p] = f; } // O(log(n)) void update(int p, U f){ static_assert(HAS_UPDATE); ASSERT(0 <= p && p < n); p += size; for(auto i = log; i >= 1; -- i) push(p >> i); ifQ{ data[p] = UT(f, data[p]); for(auto i = 1; i <= log; ++ i) refresh(p >> i); } else data_action[p] = UU(f, data_action[p]); } // O(log(n)) void update(int ql, int qr, U f){ static_assert(HAS_UPDATE); ASSERT(0 <= ql && ql <= qr && qr <= n); if(ql == qr) return; ql += size, qr += size; for(auto i = log; i >= 1; -- i){ if(ql >> i << i != ql) push(ql >> i); if(qr >> i << i != qr) push(qr >> i); } int _ql = ql, _qr = qr; for(; ql < qr; ql >>= 1, qr >>= 1){ if(ql & 1) apply(ql ++, f); if(qr & 1) apply(-- qr, f); } ql = _ql, qr = _qr; ifQ for(auto i = 1; i <= log; ++ i){ if(ql >> i << i != ql) refresh(ql >> i); if(qr >> i << i != qr) refresh(qr >> i); } } void update_beats(int ql, int qr, auto exit_rule, auto enter_rule, auto update_rule){ static_assert(HAS_QUERY && HAS_UPDATE); ASSERT(0 <= ql && ql <= qr && qr <= n); if(ql == qr) return; ql += size, qr += size; for(auto i = log; i >= 1; -- i){ if(ql >> i << i != ql) push(ql >> i); if(qr >> i << i != qr) push(qr >> i); } auto recurse = [&](auto self, int u)->void{ if(exit_rule(data[u])) return; if(enter_rule(data[u])){ apply(u, update_rule(data[u])); return; } push(u); self(self, u << 1), self(self, u << 1 | 1); refresh(u); }; int _ql = ql, _qr = qr; for(; ql < qr; ql >>= 1, qr >>= 1){ if(ql & 1) recurse(recurse, ql ++); if(qr & 1) recurse(recurse, -- qr); } ql = _ql, qr = _qr; for(auto i = 1; i <= log; ++ i){ if(ql >> i << i != ql) refresh(ql >> i); if(qr >> i << i != qr) refresh(qr >> i); } } // pred(sum[ql, r)) is T, T, ..., T, F, F, ..., F // Returns max r with T // O(log(n)) int max_pref(int ql, auto pred){ static_assert(HAS_QUERY); ASSERT(0 <= ql && ql <= n && pred(T_id)); if(ql == n) return n; ql += size; ifU for(auto i = log; i >= 1; -- i) push(ql >> i); T sum = T_id; do{ while(~ql & 1) ql >>= 1; if(!pred(TT(sum, data[ql]))){ while(ql < size){ ifU push(ql); ql = ql << 1; if(pred(TT(sum, data[ql]))) sum = TT(sum, data[ql ++]); } return ql - size; } sum = TT(sum, data[ql]); ++ ql; }while((ql & -ql) != ql); return n; } // pred(sum[l, qr)) is F, F, ..., F, T, T, ..., T // Returns min l with T // O(log(n)) int min_suff(int qr, auto pred){ static_assert(HAS_QUERY); ASSERT(0 <= qr && qr <= n && pred(T_id)); if(qr == 0) return 0; qr += size; ifU for(auto i = log; i >= 1; -- i) push(qr - 1 >> i); T sum = T_id; do{ -- qr; while(qr > 1 && qr & 1) qr >>= 1; if(!pred(TT(data[qr], sum))){ while(qr < size){ ifU push(qr); qr = qr << 1 | 1; if(pred(TT(data[qr], sum))) sum = TT(data[qr --], sum); } return qr + 1 - size; } sum = TT(data[qr], sum); }while((qr & -qr) != qr); return 0; } template friend output_stream &operator<<(output_stream &out, segment_tree_base seg){ out << "{"; for(auto i = 0; i < seg.n; ++ i){ ifQ out << seg.query(i); else out << seg.query_action(i); if(i != seg.n - 1) out << ", "; } return out << '}'; } #undef ASSERT #undef ifQ #undef ifU }; // Supports query template auto make_Q_segment_tree(F TT, T T_id){ using U = int; auto _UU = [&](U, U)->U{ return U{}; }; auto _UT = [&](U, T)->T{ return T{}; }; return segment_tree_base(TT, T_id, _UU, U{}, _UT); } // Supports update template auto make_U_segment_tree(F UU, U U_id){ using T = int; auto _TT = [&](T, T)->T{ return T{}; }; auto _UT = [&](U, T)->T{ return T{}; }; return segment_tree_base(_TT, T{}, UU, U_id, _UT); } // Supports query and update template auto make_QU_segment_tree(F1 TT, T T_id, F2 UU, U U_id, F3 UT){ return segment_tree_base(TT, T_id, UU, U_id, UT); } int main(){ cin.tie(0)->sync_with_stdio(0); cin.exceptions(ios::badbit | ios::failbit); int h, w; cin >> h >> w; vector a(h); copy_n(istream_iterator(cin), h, a.begin()); const int inf = 1e9; vector> dp(h, vector(w, inf)); for(auto j = 0; j < w; ++ j){ if(a[h - 1][j] == '.'){ dp[h - 1][j] = 0; } } auto seg = make_U_segment_tree([&](int x, int y){ return min(x, y); }, inf); for(auto i = h - 2; i >= 0; -- i){ static vector left(w), right(w); for(auto j = 0; j < w; ++ j){ if(a[i][j] == '#'){ left[j] = j; } else{ left[j] = j > 0 ? left[j - 1] : -1; } } for(auto j = w - 1; j >= 0; -- j){ if(a[i][j] == '#'){ right[j] = j; } else{ right[j] = j < w - 1 ? right[j + 1] : w; } } seg.build_action(w); for(auto j = 0; j < w; ++ j){ if(a[i][j] == '#'){ continue; } int l = max(j - dp[i + 1][j], left[j] + 1); int r = min(j + dp[i + 1][j] + 1, right[j]); seg.update(l, r, dp[i + 1][j]); } dp[i] = seg.to_array_of_updates(); for(auto j = 0; j < w; ++ j){ if(a[i][j] == '#'){ dp[i][j] = inf; } } for(auto j = 1; j < w; ++ j){ if(a[i][j] == '.' && dp[i][j - 1] + 1 < dp[i][j]){ dp[i][j] = dp[i][j - 1] + 1; } } for(auto j = w - 2; j >= 0; -- j){ if(a[i][j] == '.' && dp[i][j + 1] + 1 < dp[i][j]){ dp[i][j] = dp[i][j + 1] + 1; } } } ranges::copy(dp[0], ostream_iterator(cout, "\n")); return 0; } /* */