#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define allof(obj) (obj).begin(), (obj).end() #define range(i, l, r) for(int i=l;i>1)|y_bit)) #define bit_kth(i, k) ((i >> k)&1) #define bit_highest(i) (i?63-__builtin_clzll(i):-1) #define bit_lowest(i) (i?__builtin_ctzll(i):-1) #define sleepms(t) std::this_thread::sleep_for(std::chrono::milliseconds(t)) using ll = long long; using ld = long double; using ul = uint64_t; using pi = std::pair; using pl = std::pair; using namespace std; template std::ostream &operator<<(std::ostream &dest, const std::pair &p){ dest << p.first << ' ' << p.second; return dest; } template std::ostream &operator<<(std::ostream &dest, const std::vector> &v){ int sz = v.size(); if(sz==0) return dest; for(int i=0;i std::ostream &operator<<(std::ostream &dest, const std::vector &v){ int sz = v.size(); if(sz==0) return dest; for(int i=0;i std::ostream &operator<<(std::ostream &dest, const std::array &v){ if(sz==0) return dest; for(int i=0;i std::ostream &operator<<(std::ostream &dest, const std::set &v){ for(auto itr=v.begin();itr!=v.end();){ dest << *itr; itr++; if(itr!=v.end()) dest << ' '; } return dest; } template std::ostream &operator<<(std::ostream &dest, const std::map &v){ for(auto itr=v.begin();itr!=v.end();){ dest << '(' << itr->first << ", " << itr->second << ')'; itr++; if(itr!=v.end()) dest << '\n'; } return dest; } std::ostream &operator<<(std::ostream &dest, __int128_t value) { std::ostream::sentry s(dest); if (s) { __uint128_t tmp = value < 0 ? -value : value; char buffer[128]; char *d = std::end(buffer); do { --d; *d = "0123456789"[tmp % 10]; tmp /= 10; } while (tmp != 0); if (value < 0) { --d; *d = '-'; } int len = std::end(buffer) - d; if (dest.rdbuf()->sputn(d, len) != len) { dest.setstate(std::ios_base::badbit); } } return dest; } template vector make_vec(size_t sz, T val){return std::vector(sz, val);} template auto make_vec(size_t sz, Tail ...tail){ return std::vector(tail...))>(sz, make_vec(tail...)); } template vector read_vec(size_t sz){ std::vector v(sz); for(int i=0;i<(int)sz;i++) std::cin >> v[i]; return v; } template auto read_vec(size_t sz, Tail ...tail){ auto v = std::vector(tail...))>(sz); for(int i=0;i<(int)sz;i++) v[i] = read_vec(tail...); return v; } long long max(long long a, int b){return std::max(a, (long long)b);} long long max(int a, long long b){return std::max((long long)a, b);} long long min(long long a, int b){return std::min(a, (long long)b);} long long min(int a, long long b){return std::min((long long)a, b);} long long modulo(long long a, long long m){a %= m; return a < 0 ? a + m : a;} void io_init(){ std::cin.tie(nullptr); std::ios::sync_with_stdio(false); } #include static constexpr __uint128_t mask_0_64 = ((__uint128_t)1 << 64) - 1; //static constexpr uint64_t mask_32_64 = 0xFFFFFFFF00000000; static constexpr uint64_t mask_0_32 = 0x00000000FFFFFFFF; static constexpr uint64_t mask_48_64 = 0xFFFF000000000000; static constexpr uint64_t mask_32_48 = 0x0000FFFF00000000; static constexpr uint64_t mask_16_32 = 0x00000000FFFF0000; static constexpr uint64_t mask_0_16 = 0x000000000000FFFF; static constexpr int TABLE_SIZE_LOG = 16, TABLE_SIZE = 1 << TABLE_SIZE_LOG; using __table = std::vector>; using __table_p = std::vector, TABLE_SIZE_LOG>>; __table select_build(){ __table res(TABLE_SIZE); for(int i = 0; i < TABLE_SIZE; i++){ res[i].fill(-1); int pcnt = 0; for(int j = 0; j < TABLE_SIZE_LOG; j++) if((i >> j) & 1) res[i][pcnt++] = j; } return res; } // k-bit目以降(kも含む)に初めて現れる1の位置, 無い場合は-1 int find_next_32bit(uint32_t x, int k){ uint32_t b = x >> k; if(!b) return -1; return k + __builtin_ctz(b); } // k-bit目以降(kも含む)に初めて現れる1の位置, 無い場合は-1 int find_next_64bit(uint64_t x, int k){ uint64_t b = x >> k; if(!b) return -1; return k + __builtin_ctzll(b); } // 0 <= k <= 63 // k-bit目以前(kも含む)に初めて現れる1の位置, 無い場合は-1 int find_prev_64bit(uint64_t x, int k){ uint64_t b = x << (63 - k); if(!b) return -1; return k - __builtin_clzll(b); } // k番目(0-indexed)の1の場所(0-indexed)を返す. 無い場合壊れる int select_32bit(uint32_t x, int k){ static __table table = select_build(); int r = __builtin_popcount(x & mask_0_16); if(r > k) return table[x & mask_0_16][k]; return 16 + table[(x & mask_16_32) >> 16][k - r]; } // k番目(0-indexed)の1の場所(0-indexed)を返す. 無い場合壊れる int select_64bit(uint64_t x, int k){ static __table table = select_build(); int r = __builtin_popcount(x & mask_0_32); if(r > k){ int rr = __builtin_popcount(x & mask_0_16); if(rr > k) return table[x & mask_0_16][k]; else return 16 + table[(x & mask_16_32) >> 16][k - rr]; }else{ k -= r; int lr = __builtin_popcountll(x & mask_32_48); if(lr > k) return 32 + table[(x & mask_32_48) >> 32][k]; else return 48 + table[(x & mask_48_64) >> 48][k - lr]; } } // 先頭k_bit(0 <= k <= 32)の1の数 int rank_32bit(uint32_t x, int k){ return k == 32 ? __builtin_popcount(x) : __builtin_popcount(x & ((1ULL << k) - 1)); } // 先頭k_bit(0 <= k <= 64)の1の数 int rank_64bit(uint64_t x, int k){ return k == 64 ? __builtin_popcountll(x) : __builtin_popcountll(x & ((1ULL << k) - 1)); } // 128bit int pop_count_128bit(__uint128_t x){ return __builtin_popcountll(x >> 64) + __builtin_popcountll(x & mask_0_64); } int rank_128bit(__uint128_t x, int k){ if(k == 128) return pop_count_128bit(x); if(k < 64) return __builtin_popcountll((x & mask_0_64) & ((1ULL << k) - 1)); k -= 64; return __builtin_popcountll(x & mask_0_64) + __builtin_popcountll((x >> 64) & ((1ULL << k) - 1)); } // k番目の1, 無い場合壊れる int select1_128bit(__uint128_t x, int k){ int left_pop = __builtin_popcountll(x & mask_0_64); if(left_pop > k) return select_64bit(x & mask_0_64, k); return 64 + select_64bit(x >> 64, k - left_pop); } // k番目の0, 無い場合壊れる int select0_128bit(__uint128_t x, int k){ __uint128_t y = ~x; int left_unpop = __builtin_popcountll(y & mask_0_64); if(left_unpop > k) return select_64bit(y & mask_0_64, k); return 64 + select_64bit(y >> 64, k - left_unpop); } // k-bit目以降(kも含む)に初めて現れる1の位置, 無い場合は-1 int find_next_128bit(__uint128_t x, int k){ __uint128_t b = x >> k; if(!b) return -1; // 末尾64bitが0 if(!(b & mask_0_64)) return k + 64 + __builtin_ctzll(b >> 64); return k + __builtin_ctzll(b); } // 0 <= k <= 63 // k-bit目以前(kも含む)に初めて現れる1の位置, 無い場合は-1 int find_prev_128bit(__uint128_t x, int k){ __uint128_t b = x << (127 - k); if(!b) return -1; // 先頭64bitが0 if(!(b >> 64)) return k - 64 - __builtin_clzll(b); return k - __builtin_clzll(b >> 64); } template struct binary_indexed_tree{ int M, H; std::vector sum; binary_indexed_tree(){} binary_indexed_tree(int N): M(N), H(31 - __builtin_clz(M)), sum(M + 1 , 0){} binary_indexed_tree(const std::vector &v): M(v.size()), H(31 - __builtin_clz(M)), sum(1){ sum.insert(sum.begin() + 1, v.begin(), v.end()); for(int i = 1; i <= v.size(); i++){ int nxt = i + (i & (-i)); if(nxt <= M) sum[nxt] += sum[i]; } } void update(int k, Val x){ for(int i = k + 1; i <= M; i += (i & (-i))) sum[i] += x; } Val query(int r){ Val ret = 0; for(int k = r; k > 0; k -= (k & (-k))) ret += sum[k]; return ret; } Val query(int l, int r){ return query(r) - query(l); } // sum[0, k]がx以上になるような最小のkとsum[0, k], 無い場合は{M, 総和} // sumが単調非減少であることが必要 using p = std::pair; p lower_bound(Val x){ int v = 1 << H, h = H; Val s = 0, t = 0; while(h--){ if(M < v) v -= 1 << h; else if(x <= s + sum[v]) t = s + sum[v], v -= 1 << h; else s += sum[v], v += 1 << h; } if(v == M + 1) return {M, s}; return (x <= s + sum[v] ? p{v - 1, s + sum[v]} : p{v, t}); } }; // 同じサイズのbitset同士でしか演算できない // サイズを変更する場合resize // n, m, im: 最大サイズ, 最大ブロック, 内部的なサイズ(これ以降に1がないことが保証されている) // rank, selectを実行する前にブロックごとのbinary_indexed_treeを再計算 struct dynamic_bitset_rank_select{ static constexpr int BITLEN = 64, REM = 63, SHIFT = 6; int n, m, im; std::vector v; binary_indexed_tree bit_count; uint64_t rightmost_mask(){ return !(n & REM) ? ~0ULL : (1ULL << (n & REM)) - 1; } dynamic_bitset_rank_select(): n(0), m(0), im(0){} dynamic_bitset_rank_select(const dynamic_bitset_rank_select &r): n(r.n), m(r.m), im(r.im), v(r.v.begin(), r.v.begin() + r.im), bit_updated(false){} dynamic_bitset_rank_select(int n, bool f = 0): n(n), m((n + REM) >> SHIFT), bit_updated(false){ if(f){ im = m; v.resize(m, ~0ULL); v.back() &= rightmost_mask(); }else im = 0; } // stringの左を0bit目とする dynamic_bitset_rank_select(const std::string &s, char one = '1'): n(s.size()), m((n + REM) >> SHIFT), im(0), bit_updated(false){ uint64_t sum = 0; for(int i = 0, j = 0, t = 0; i < n; i++){ sum += (uint64_t)(s[i] == one) << j; if(i == n - 1 || j == REM){ t++; v.push_back(sum); if(sum) im = t; sum = j = 0; }else j++; } } int size(){ return n; } void set(int k, bool f){ assert(0 <= k && k < n); int block = k >> SHIFT; if(f){ if(block >= im) im = block + 1; while(block >= v.size()) v.resize(std::min((int)v.size() * 2 + 1, m), 0); if(bit_updated && !((v[block] >> (k & REM)) & 1)) bit_count.update(block, 1); v[block] |= (1ULL << (k & REM)); }else if(block < im){ if(bit_updated && ((v[block] >> (k & REM)) & 1)) bit_count.update(block, -1); v[block] &= ~(1ULL << (k & REM)); } } bool get(int k){ return (k >> SHIFT) < im ? (v[k >> SHIFT] >> (k & REM)) & 1 : 0; } bool any(){ if(bit_updated) return bit_count.query(m); for(int i = 0; i < im; i++) if(v[i]) return true; return false; } bool all(){ if(bit_updated) return bit_count.query(m) == n; if(im != m) return false; for(int i = 0; i < m - 1; i++) if(v[i] != ~0ULL) return false; if(v[m - 1] != rightmost_mask()) return false; return true; } bool none(){ return !any(); } /* void resize(int s){ bit_updated = false; m = (s + REM) >> SHIFT; if(m < im) v.resize(m), im = m; n = s; if(m == im) v[m - 1] &= rightmost_mask(); } */ dynamic_bitset_rank_select operator ~(){ dynamic_bitset_rank_select res = *this; res.v.resize(m, ~0ULL); for(int i = 0; i < res.im; i++) res.v[i] = ~res.v[i]; res.im = res.m; res.v[m - 1] &= res.rightmost_mask(); return res; } dynamic_bitset_rank_select operator ^ (const dynamic_bitset_rank_select &r){ dynamic_bitset_rank_select res(*this); return res ^= r; } dynamic_bitset_rank_select operator | (const dynamic_bitset_rank_select &r){ dynamic_bitset_rank_select res(*this); return res |= r; } dynamic_bitset_rank_select operator & (const dynamic_bitset_rank_select &r){ dynamic_bitset_rank_select res(*this); return res &= r; } dynamic_bitset_rank_select operator ^= (const dynamic_bitset_rank_select &r){ assert(n == r.n); bit_updated = false; if(im < r.im){ im = r.im; v.resize(r.im, 0); } for(int i = 0; i < r.im; i++) v[i] ^= r.v[i]; return *this; } dynamic_bitset_rank_select operator |= (const dynamic_bitset_rank_select &r){ assert(n == r.n); bit_updated = false; if(im < r.im){ im = r.im; v.resize(r.im, 0); } for(int i = 0; i < r.im; i++) v[i] |= r.v[i]; return *this; } dynamic_bitset_rank_select operator &= (const dynamic_bitset_rank_select &r){ assert(n == r.n); bit_updated = false; if(im > r.im){ im = r.im; v.resize(im); } for(int i = 0; i < im; i++) v[i] &= r.v[i]; return *this; } // 全てのビットが等しく, かつサイズも同じか bool operator == (const dynamic_bitset_rank_select &r){ if(n != r.n) return false; for(int i = 0; i < std::min(im, r.im); i++) if(v[i] != r.v[i]) return false; if(im > r.im){ for(int i = r.im; i < im; i++) if(v[i]) return false; }else{ for(int i = im; i < r.im; i++) if(r.v[i]) return false; } return true; } bool operator != (const dynamic_bitset_rank_select &r){ return !(*this == r); } // l |= r << s, l = rでもok static void lshift_or(dynamic_bitset_rank_select &l, dynamic_bitset_rank_select &r, int s){ assert(l.n == r.n); l.bit_updated = false; int t = s & REM, k = s >> SHIFT; if(!t){ int imr = std::min(r.m, r.im + k); l.im = std::max(l.im, imr); if(imr > l.v.size()) l.v.resize(imr, 0); for(int i = imr - 1; i >= k; i--) l.v[i] |= r.v[i - k]; if(imr == l.m) l.v.back() &= l.rightmost_mask(); return; } int imr = std::min(r.m, r.im + k + 1); l.im = std::max(l.im, imr); if(imr > l.v.size()) l.v.resize(imr, 0); int upper_bit = 64 - t; for(int i = imr - 1; i >= k; i--){ if(i == k) l.v[i] |= r.v[i - k] << t; else l.v[i] |= (r.v[i - k] << t) | (r.v[i - k - 1] >> upper_bit); } if(imr == l.m) l.v.back() &= l.rightmost_mask(); } // l ^= r << s, l = rでもok static void lshift_xor(dynamic_bitset_rank_select &l, dynamic_bitset_rank_select &r, int s){ assert(l.n == r.n); l.bit_updated = false; int t = s & REM, k = s >> SHIFT; if(!t){ int imr = std::min(r.m, r.im + k); l.im = std::max(l.im, imr); if(imr > l.v.size()) l.v.resize(imr, 0); for(int i = imr - 1; i >= k; i--) l.v[i] ^= r.v[i - k]; if(imr == l.m) l.v.back() &= l.rightmost_mask(); return; } int imr = std::min(r.m, r.im + k + 1); l.im = std::max(l.im, imr); if(imr > l.v.size()) l.v.resize(imr, 0); int upper_bit = 64 - t; for(int i = imr - 1; i >= k; i--){ if(i == k) l.v[i] ^= r.v[i - k] << t; else l.v[i] ^= (r.v[i - k] << t) | (r.v[i - k - 1] >> upper_bit); } if(imr == l.m) l.v.back() &= l.rightmost_mask(); } // l &= r << s, l = rでもok static void lshift_and(dynamic_bitset_rank_select &l, dynamic_bitset_rank_select &r, int s){ assert(l.n == r.n); l.bit_updated = false; int t = s & REM, k = s >> SHIFT; if(!t){ int imr = std::min(l.im, r.im + k); for(int i = imr - 1; i >= 0; i--) l.v[i] &= (i >= k ? r.v[i - k] : 0); for(int i = l.im - 1; i >= imr; i--) l.v[i] = 0; l.im = imr; return; } int imr = std::min(l.im, r.im + k + 1); int upper_bit = 64 - t; for(int i = imr - 1; i >= 0; i--){ if(i < k) l.v[i] = 0; else if(i == k) l.v[i] &= r.v[i - k] << t; else l.v[i] &= (r.v[i - k] << t) | (r.v[i - k - 1] >> upper_bit); } for(int i = l.im - 1; i >= imr; i--) l.v[i] = 0; l.im = imr; } dynamic_bitset_rank_select operator <<= (const int s){ assert(0 <= s); bit_updated = false; int t = s & REM, k = s >> SHIFT; if(!t){ im = std::min(m, im + k); if(im > v.size()) v.resize(im, 0); for(int i = im - 1; i >= 0; i--) v[i] = (i >= k ? v[i - k] : 0); if(im == m) v.back() &= rightmost_mask(); return *this; } im = std::min(m, im + k + 1); if(im > v.size()) v.resize(im, 0); int upper_bit = 64 - t; for(int i = im - 1; i >= 0; i--){ if(i < k) v[i] = 0; else if(i == k) v[i] = v[i - k] << t; else v[i] = (v[i - k] << t) | (v[i - k - 1] >> upper_bit); } if(im == m) v.back() &= rightmost_mask(); return *this; } dynamic_bitset_rank_select operator >>= (const int s){ assert(0 <= s); bit_updated = false; int t = s & REM, k = s >> SHIFT; im -= k; if(!t){ for(int i = 0; i < im; i++) v[i] = v[i + k]; for(int i = std::max(0, im); i < im + k; i++) v[i] = 0; if(im < 0) im = 0; return *this; } int upper_bit = 64 - t; for(int i = 0; i < im; i++){ if(i + k == (int)v.size() - 1) v[i] = v[i + k] >> t; else v[i] = (v[i + k] >> t) | (v[i + k + 1] << upper_bit); } for(int i = std::max(0, im); i < im + k; i++) v[i] = 0; if(im < 0) im = 0; return *this; } dynamic_bitset_rank_select operator << (const int s){ dynamic_bitset_rank_select res(*this); return res <<= s; } dynamic_bitset_rank_select operator >> (const int s){ dynamic_bitset_rank_select res(*this); return res >>= s; } bool bit_updated; void bit_recalc(){ if(bit_updated) return; if(bit_count.sum.size() != m + 1) bit_count = binary_indexed_tree(m); for(int i = 0; i < m; i++){ if(i < im) bit_count.sum[i + 1] = __builtin_popcountll(v[i]); else bit_count.sum[i + 1] = 0; } for(int i = 1; i <= m; i++){ int nxt = i + (i & (-i)); if(nxt <= m) bit_count.sum[nxt] += bit_count.sum[i]; } bit_updated = true; } int pop_count(){ if(!bit_updated) bit_recalc(); return bit_count.query(m); } int rank1(int r){ assert(0 <= r && r <= n); if(!bit_updated) bit_recalc(); int block = r >> SHIFT; return bit_count.query(block) + (im <= block ? 0 : rank_64bit(v[block], r & REM)); } int rank0(int r){ assert(0 <= r && r <= n); return r - rank1(r); } // k個目(0-indexed)の1, 無い場合は-1 int select1(int k){ if(!bit_updated) bit_recalc(); auto [b, c] = bit_count.lower_bound(k + 1); if(b == m) return -1; return (b << SHIFT) + select_64bit(v[b], k - c + __builtin_popcountll(v[b])); } // k個目(0-indexed)の0, 無い場合は-1 int select0(int k){ if(!bit_updated) bit_recalc(); int x = k + 1, y = 1 << bit_count.H, h = bit_count.H; int s = 0, t = 0; while(h--){ if(bit_count.M < y) y -= 1 << h; else{ int sum_zero = s + (1 << (h + 1 + SHIFT)) - bit_count.sum[y]; // 区間長 = 2^(h + 1) * 64 = 1 << (h + 1 + SHIFT) if(x <= sum_zero) t = sum_zero, y -= 1 << h; else s = sum_zero, y += 1 << h; } } if(y == bit_count.M + 1) return -1; int b, c; if(x <= s + (1 << SHIFT) - bit_count.sum[y]) b = y - 1, c = s + (1 << SHIFT) - bit_count.sum[y]; else b = y, c = t; int i = (b << SHIFT); if(b >= im) i += k - c + BITLEN; else i += select_64bit(~v[b], k - c + __builtin_popcountll(~v[b])); return i >= n ? -1 : i; } // i以降(i含む)の1, 無い場合は-1 int find_next1(int i){ assert(0 <= i && i < n); if((i >> SHIFT) >= im) return -1; int _i = i & REM, _j = find_next_64bit(v[i >> SHIFT], _i); if(_j != -1) return i - _i + _j; return select1(rank1(i)); } // i以前(i含む)の1, 無い場合は-1 int find_prev1(int i){ assert(0 <= i && i < n); if((i >> SHIFT) >= im){ if(!im) return -1; i = (im << SHIFT) - 1; } int _i = i & REM, _j = find_prev_64bit(v[i >> SHIFT], _i); if(_j != -1) return i - _i + _j; int r = rank1(i + 1); if(!r) return -1; return select1(r - 1); } // i以降(i含む)の0, 無い場合は-1 int find_next0(int i){ assert(0 <= i && i < n); if((i >> SHIFT) >= im) return i; int _i = i & REM, _j = find_next_64bit(~v[i >> SHIFT], _i); if(_j != -1){ int res = i - _i + _j; return res >= n ? -1 : res; } return select0(rank0(i)); } // i以前(i含む)の0, 無い場合は-1 int find_prev0(int i){ assert(0 <= i && i < n); if((i >> SHIFT) >= im) return i; int _i = i & REM, _j = find_prev_64bit(~v[i >> SHIFT], _i); if(_j != -1) return i - _i + _j; int r = rank0(i + 1); if(!r) return -1; return select0(r - 1); } }; std::ostream &operator<<(std::ostream &dest, const dynamic_bitset_rank_select &v){ if(!v.n) return dest; int cnt = 0; for(int i = 0; i < v.m; i++){ if(i >= v.im){ for(int j = 0; j < 64 && cnt < v.n; j++, cnt++) dest << 0; }else{ for(int j = 0; j < 64 && cnt < v.n; j++, cnt++) dest << ((v.v[i] >> j) & 1); } if(i != v.m - 1) dest << ' '; } return dest; } // {begin, end, f: Itr::value_type -> uint} template void bucket_sort(Itr first, Itr last, F f){ std::vector> tmp(1); int sz = 1; for(auto itr = first; itr != last; itr++){ int key = f(*itr); while(sz <= key) tmp.resize(sz *= 2); tmp[key].push_back(*itr); } int row = 0, col = 0; for(auto itr = first; itr != last; itr++, col++){ while(tmp[row].size() <= col) row++, col = 0; *itr = tmp[row][col]; } } template void bucket_sort2(Itr first, Itr last, F f){ std::vector> tmp(3001); for(auto itr = first; itr != last; itr++){ int key = f(*itr); tmp[key].push_back(*itr); } int row = 0, col = 0; for(auto itr = first; itr != last; itr++, col++){ while(tmp[row].size() <= col) row++, col = 0; *itr = tmp[row][col]; } } int main(){ io_init(); int h, w, n; std::cin >> h >> w >> n; auto v = make_vec(h, w, 0); range(i, 0, n){ int a, b; std::cin >> a >> b; a--, b--; v[a][b] = 1; } ll ans = 0; vector d(w, 0); range(i, 0, h){ range(j, 0, w) d[j] = (v[i][j] ? 0 : d[j] + 1); vector> E; range(j, 0, w) if(i >= d[j]) E.push_back({i - d[j], j}); //sort(allof(E)); bucket_sort2(allof(E), [](pair &a){return a.first;}); reverse(allof(E)); int S = w * (w + 1) / 2; dynamic_bitset_rank_select bit(w, 1); for(int j = i, idx = 0; j >= 0; j--){ while(idx < E.size() && E[idx].first == j){ auto [_, col] = E[idx++]; int l = bit.find_prev0(col) + 1; int r = bit.find_next0(col); if(r == -1) r = w; bit.set(col, 0); S -= (r - l) * (r - l + 1) / 2; S += (col - l) * (col - l + 1) / 2; S += (r - col - 1) * (r - col) / 2; } ans += S; } } std::cout << ans << '\n'; }