#pragma GCC optimize("unroll-loops") #pragma GCC optimize("Ofast") // hloya template v26 // ░░░░░░░▄▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▄░░░░░░ // ░░░░░░█░░▄▀▀▀▀▀▀▀▀▀▀▀▀▀▄░░█░░░░░ // ░░░░░░█░█░▀░░░░░▀░░▀░░░░█░█░░░░░ // ░░░░░░█░█░░░░░░░░▄▀▀▄░▀░█░█▄▀▀▄░ // █▀▀█▄░█░█░░▀░░░░░█░░░▀▄▄█▄▀░░░█░ // ▀▄▄░▀██░█▄░▀░░░▄▄▀░░░░░░░░░░░░▀▄ // ░░▀█▄▄█░█░░░░▄░░█░░░▄█░░░▄░▄█░░█ // ░░░░░▀█░▀▄▀░░░░░█░██░▄░░▄░░▄░███ // ░░░░░▄█▄░░▀▀▀▀▀▀▀▀▄░░▀▀▀▀▀▀▀░▄▀░ // ░░░░█░░▄█▀█▀▀█▀▀▀▀▀▀█▀▀█▀█▀▀█░░░ // ░░░░▀▀▀▀░░▀▀▀░░░░░░░░▀▀▀░░▀▀░░░░ #include <bits/stdc++.h> using namespace std; bool dbg = 0; clock_t start_time = clock(); #define current_time \ fixed << setprecision(6) << (ld)(clock() - start_time) / CLOCKS_PER_SEC #define f first #define s second #define mp make_pair #define mt make_tuple #define pb push_back #define eb emplace_back #define all(v) (v).begin(), (v).end() #define sz(v) ((int)(v).size()) #define sqr(x) ((x) * (x)) #define ull unsigned long long #define ll long long #define ld long double #define pii pair<int, int> #define umap unordered_map<int, int> #define files1 freopen("input.txt", "r", stdin) #define files2 freopen("output.txt", "w", stdout) #define files \ files1; \ files2 #define fast_io \ ios_base::sync_with_stdio(0); \ cin.tie(0) // #define endl '\n' #define ln(i, n) " \n"[(i) == (n)-1] void bad(string mes = "NO") { cout << mes; exit(0); } void bad(int mes) { cout << mes; exit(0); } template <typename T> string bin(T x, int st = 2) { string ans = ""; while (x > 0) { ans += char('0' + x % st); x /= st; } reverse(ans.begin(), ans.end()); return ans.empty() ? "0" : ans; } mt19937_64 mt_rand(228 // chrono::system_clock::now().time_since_epoch().count() ); template <typename T1, typename T2> inline bool upmax(T1 &a, T2 b) { return (a < b ? (a = b, true) : false); } template <typename T1, typename T2> inline bool upmin(T1 &a, T2 b) { return (b < a ? (a = b, true) : false); } // inline int popcount(int x){ // int count = 0; // __asm__ volatile("POPCNT %1, %0;":"=r"(count):"r"(x):); // return count; // } template <typename T> T input() { T ans = 0, m = 1; char c = ' '; while (!((c >= '0' && c <= '9') || c == '-')) { c = getchar(); } if (c == '-') m = -1, c = getchar(); while (c >= '0' && c <= '9') { ans = ans * 10 + (c - '0'), c = getchar(); } return ans * m; } template <typename T> T gcd(T a, T b) { while (b) { a %= b; swap(a, b); } return a; } template <typename T> void read(T &a) { a = input<T>(); } template <typename T> void read(T &a, T &b) { read(a), read(b); } template <typename T> void read(T &a, T &b, T &c) { read(a, b), read(c); } template <typename T> void read(T &a, T &b, T &c, T &d) { read(a, b), read(c, d); } const int inf = 1e9 + 20; const short short_inf = 3e4 + 20; const long double eps = 1e-12; const int maxn = (int)1500 + 3, base = 998244353; const ll llinf = 2e18 + 5; const int mod = 1e9 + 7; struct Bitset128 { vector<__uint128_t> a; Bitset128(int n) { a.resize((n + 127) / 128); } void set(int x) { a[x / 128] |= (1ULL << (x % 128)); } void reset(int x) { a[x / 128] &= ~(1ULL << (x % 128)); } bool get(int x) { return a[x / 128] & (1ULL << (x % 128)); } void clear() { for (int i = 0; i < a.size(); i++) { a[i] = 0; } } void operator|=(const Bitset128& other) { for (int i = 0; i < a.size(); i++) { a[i] |= other.a[i]; } } void operator&=(const Bitset128& other) { for (int i = 0; i < a.size(); i++) { a[i] &= other.a[i]; } } }; struct Bitset { vector<uint64_t> a; Bitset(int n) { a.resize((n + 63) / 64); } void set(int x) { a[x / 64] |= (1ULL << (x % 64)); } void reset(int x) { a[x / 64] &= ~(1ULL << (x % 64)); } bool get(int x) { return a[x / 64] & (1ULL << (x % 64)); } void clear() { for (int i = 0; i < a.size(); i++) { a[i] = 0; } } void operator|=(const Bitset& other) { ccbits = 0; for (int i = 0; i < a.size(); i++) { a[i] |= other.a[i]; ccbits += __builtin_popcountll(a[i]); } } int ccbits = 0; }; int solve(int n, vector<vector<int>> mat) { vector<int> perm(n); for (int i = 0; i < n; i++) { perm[i] = i; } random_shuffle(all(perm)); vector<vector<int>> updated_mat = mat; for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { updated_mat[perm[i]][perm[j]] = mat[i][j]; } } mat = updated_mat; vector<vector<int>> dist(n, vector<int>(n, inf)); for (int i = 0; i < n; i++) { dist[i][i] = 0; for (int j = 0; j < n; j++) { if (mat[i][j] == 1) { dist[i][j] = 1; } } } for (int k = 0; k < n; k++) { for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]); } } } vector<vector<pair<int,int>>> sorted_dists(n+1); vector<vector<Bitset>> dp(n+1, vector<Bitset>(n, Bitset(n))); for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { if (dist[i][j] <= n) { sorted_dists[dist[i][j]].emplace_back(i, j); } else { throw; } } } for (int d = 0; d <= n; ++d) { if (d > 0) { dp[d] = dp[d-1]; } for (auto [i, j] : sorted_dists[d]) { dp[d][i].set(j); dp[d][j].set(i); } } auto can = [&](int x) ->bool { Bitset bs(n); for (int a = 0; a < n; ++a) { for (int b = 0; b < n; ++b) { bool ok = true; for (int u = 0; u < n && ok; ++u) { // d[u][v] <= x or d[u][a] + d[b][v] <= x or d[u][b] + d[a][v] <= x bs.clear(); bs |= dp[x][u]; int d2 = x - dist[u][a]; if (d2 >= 0) { bs |= dp[d2][b]; } int d3 = x - dist[u][b]; if (d3 >= 0) { bs |= dp[d3][a]; } if (bs.ccbits < n) { ok = false; } } if (ok) { return true; } } } return false; }; int l = 0, r = n; while (l < r) { int m = (l + r) / 2; if (can(m)) { r = m; } else { l = m + 1; } } return l; } int solveBrute(int n, vector<vector<int>> mat) { vector<vector<int>> dist(n, vector<int>(n, inf)); for (int i = 0; i < n; i++) { dist[i][i] = 0; for (int j = 0; j < n; j++) { if (mat[i][j] == 1) { dist[i][j] = 1; } } } for (int k = 0; k < n; k++) { for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]); } } } int ans = inf; for (int u = 0; u < n; u++) { for (int v = 0; v < n; v++) { int curres = 0; for (int a = 0; a < n; a++) { for (int b = 0; b < n; b++) { curres = max(curres, min({dist[a][b], dist[a][u] + dist[v][b], dist[a][v] + dist[u][b]})); } } ans = min(ans, curres); } } return ans; } int main() { // files1; fast_io; int t; cin >> t; while (t--) { int n; cin >> n; vector<vector<int>> mat(n, vector<int>(n)); string line; for (int i = 0; i < n; i++) { cin >> line; for (int j = 0; j < n; j++) { mat[i][j] = line[j] - '0'; } } cout << solve(n, mat) << endl; } return 0; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 | #pragma GCC optimize("unroll-loops") #pragma GCC optimize("Ofast") // hloya template v26 // ░░░░░░░▄▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▄░░░░░░ // ░░░░░░█░░▄▀▀▀▀▀▀▀▀▀▀▀▀▀▄░░█░░░░░ // ░░░░░░█░█░▀░░░░░▀░░▀░░░░█░█░░░░░ // ░░░░░░█░█░░░░░░░░▄▀▀▄░▀░█░█▄▀▀▄░ // █▀▀█▄░█░█░░▀░░░░░█░░░▀▄▄█▄▀░░░█░ // ▀▄▄░▀██░█▄░▀░░░▄▄▀░░░░░░░░░░░░▀▄ // ░░▀█▄▄█░█░░░░▄░░█░░░▄█░░░▄░▄█░░█ // ░░░░░▀█░▀▄▀░░░░░█░██░▄░░▄░░▄░███ // ░░░░░▄█▄░░▀▀▀▀▀▀▀▀▄░░▀▀▀▀▀▀▀░▄▀░ // ░░░░█░░▄█▀█▀▀█▀▀▀▀▀▀█▀▀█▀█▀▀█░░░ // ░░░░▀▀▀▀░░▀▀▀░░░░░░░░▀▀▀░░▀▀░░░░ #include <bits/stdc++.h> using namespace std; bool dbg = 0; clock_t start_time = clock(); #define current_time \ fixed << setprecision(6) << (ld)(clock() - start_time) / CLOCKS_PER_SEC #define f first #define s second #define mp make_pair #define mt make_tuple #define pb push_back #define eb emplace_back #define all(v) (v).begin(), (v).end() #define sz(v) ((int)(v).size()) #define sqr(x) ((x) * (x)) #define ull unsigned long long #define ll long long #define ld long double #define pii pair<int, int> #define umap unordered_map<int, int> #define files1 freopen("input.txt", "r", stdin) #define files2 freopen("output.txt", "w", stdout) #define files \ files1; \ files2 #define fast_io \ ios_base::sync_with_stdio(0); \ cin.tie(0) // #define endl '\n' #define ln(i, n) " \n"[(i) == (n)-1] void bad(string mes = "NO") { cout << mes; exit(0); } void bad(int mes) { cout << mes; exit(0); } template <typename T> string bin(T x, int st = 2) { string ans = ""; while (x > 0) { ans += char('0' + x % st); x /= st; } reverse(ans.begin(), ans.end()); return ans.empty() ? "0" : ans; } mt19937_64 mt_rand(228 // chrono::system_clock::now().time_since_epoch().count() ); template <typename T1, typename T2> inline bool upmax(T1 &a, T2 b) { return (a < b ? (a = b, true) : false); } template <typename T1, typename T2> inline bool upmin(T1 &a, T2 b) { return (b < a ? (a = b, true) : false); } // inline int popcount(int x){ // int count = 0; // __asm__ volatile("POPCNT %1, %0;":"=r"(count):"r"(x):); // return count; // } template <typename T> T input() { T ans = 0, m = 1; char c = ' '; while (!((c >= '0' && c <= '9') || c == '-')) { c = getchar(); } if (c == '-') m = -1, c = getchar(); while (c >= '0' && c <= '9') { ans = ans * 10 + (c - '0'), c = getchar(); } return ans * m; } template <typename T> T gcd(T a, T b) { while (b) { a %= b; swap(a, b); } return a; } template <typename T> void read(T &a) { a = input<T>(); } template <typename T> void read(T &a, T &b) { read(a), read(b); } template <typename T> void read(T &a, T &b, T &c) { read(a, b), read(c); } template <typename T> void read(T &a, T &b, T &c, T &d) { read(a, b), read(c, d); } const int inf = 1e9 + 20; const short short_inf = 3e4 + 20; const long double eps = 1e-12; const int maxn = (int)1500 + 3, base = 998244353; const ll llinf = 2e18 + 5; const int mod = 1e9 + 7; struct Bitset128 { vector<__uint128_t> a; Bitset128(int n) { a.resize((n + 127) / 128); } void set(int x) { a[x / 128] |= (1ULL << (x % 128)); } void reset(int x) { a[x / 128] &= ~(1ULL << (x % 128)); } bool get(int x) { return a[x / 128] & (1ULL << (x % 128)); } void clear() { for (int i = 0; i < a.size(); i++) { a[i] = 0; } } void operator|=(const Bitset128& other) { for (int i = 0; i < a.size(); i++) { a[i] |= other.a[i]; } } void operator&=(const Bitset128& other) { for (int i = 0; i < a.size(); i++) { a[i] &= other.a[i]; } } }; struct Bitset { vector<uint64_t> a; Bitset(int n) { a.resize((n + 63) / 64); } void set(int x) { a[x / 64] |= (1ULL << (x % 64)); } void reset(int x) { a[x / 64] &= ~(1ULL << (x % 64)); } bool get(int x) { return a[x / 64] & (1ULL << (x % 64)); } void clear() { for (int i = 0; i < a.size(); i++) { a[i] = 0; } } void operator|=(const Bitset& other) { ccbits = 0; for (int i = 0; i < a.size(); i++) { a[i] |= other.a[i]; ccbits += __builtin_popcountll(a[i]); } } int ccbits = 0; }; int solve(int n, vector<vector<int>> mat) { vector<int> perm(n); for (int i = 0; i < n; i++) { perm[i] = i; } random_shuffle(all(perm)); vector<vector<int>> updated_mat = mat; for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { updated_mat[perm[i]][perm[j]] = mat[i][j]; } } mat = updated_mat; vector<vector<int>> dist(n, vector<int>(n, inf)); for (int i = 0; i < n; i++) { dist[i][i] = 0; for (int j = 0; j < n; j++) { if (mat[i][j] == 1) { dist[i][j] = 1; } } } for (int k = 0; k < n; k++) { for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]); } } } vector<vector<pair<int,int>>> sorted_dists(n+1); vector<vector<Bitset>> dp(n+1, vector<Bitset>(n, Bitset(n))); for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { if (dist[i][j] <= n) { sorted_dists[dist[i][j]].emplace_back(i, j); } else { throw; } } } for (int d = 0; d <= n; ++d) { if (d > 0) { dp[d] = dp[d-1]; } for (auto [i, j] : sorted_dists[d]) { dp[d][i].set(j); dp[d][j].set(i); } } auto can = [&](int x) ->bool { Bitset bs(n); for (int a = 0; a < n; ++a) { for (int b = 0; b < n; ++b) { bool ok = true; for (int u = 0; u < n && ok; ++u) { // d[u][v] <= x or d[u][a] + d[b][v] <= x or d[u][b] + d[a][v] <= x bs.clear(); bs |= dp[x][u]; int d2 = x - dist[u][a]; if (d2 >= 0) { bs |= dp[d2][b]; } int d3 = x - dist[u][b]; if (d3 >= 0) { bs |= dp[d3][a]; } if (bs.ccbits < n) { ok = false; } } if (ok) { return true; } } } return false; }; int l = 0, r = n; while (l < r) { int m = (l + r) / 2; if (can(m)) { r = m; } else { l = m + 1; } } return l; } int solveBrute(int n, vector<vector<int>> mat) { vector<vector<int>> dist(n, vector<int>(n, inf)); for (int i = 0; i < n; i++) { dist[i][i] = 0; for (int j = 0; j < n; j++) { if (mat[i][j] == 1) { dist[i][j] = 1; } } } for (int k = 0; k < n; k++) { for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]); } } } int ans = inf; for (int u = 0; u < n; u++) { for (int v = 0; v < n; v++) { int curres = 0; for (int a = 0; a < n; a++) { for (int b = 0; b < n; b++) { curres = max(curres, min({dist[a][b], dist[a][u] + dist[v][b], dist[a][v] + dist[u][b]})); } } ans = min(ans, curres); } } return ans; } int main() { // files1; fast_io; int t; cin >> t; while (t--) { int n; cin >> n; vector<vector<int>> mat(n, vector<int>(n)); string line; for (int i = 0; i < n; i++) { cin >> line; for (int j = 0; j < n; j++) { mat[i][j] = line[j] - '0'; } } cout << solve(n, mat) << endl; } return 0; } |