#include <cstdio> #include <algorithm> #include <vector> #include <ctime> #include <cmath> using namespace std; const int MAX_SIZE = 402; const int INF = 100000; const int BRUT_THRESHOLD = 200; char adj[MAX_SIZE][MAX_SIZE]; int dist[MAX_SIZE][MAX_SIZE]; int perm[MAX_SIZE]; vector<pair<int,int>> paths_of_length[MAX_SIZE]; vector<int> firsts[MAX_SIZE]; vector<int> seconds[MAX_SIZE]; inline int turboMin(int a, int b) { return b + ((a-b) & (a-b)>>31); } inline int turboMax(int a, int b) { return a - ((a-b) & (a-b)>>31); } void calcDist(int n) { for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { if (i == j) { dist[i][j] = 0; } else if (adj[i][j] == '1') { dist[i][j] = 1; } else { dist[i][j] = INF; } } } for (int k = 0; k < n; k++) { for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { if (dist[i][j] > dist[i][k] + dist[k][j]) { dist[i][j] = dist[i][k] + dist[k][j]; } } } } for (int i = 0; i <= n; i++) { paths_of_length[i].clear(); } for (int i = 0; i < n; i++) { for (int j = i + 1; j < n; j++) { paths_of_length[dist[i][j]].emplace_back(i, j); } } for (int i = 0; i <= n; i++) { random_shuffle(paths_of_length[i].begin(), paths_of_length[i].end()); } for (int i = 0; i <= n; i++) { firsts[i].resize(paths_of_length[i].size()); seconds[i].resize(paths_of_length[i].size()); for (size_t j = 0; j < paths_of_length[i].size(); j++) { firsts[i][j] = paths_of_length[i][j].first; seconds[i][j] = paths_of_length[i][j].second; } } } int best_for_2(int n, int a, int b, int curBest) { int maxTeleLen = 0; int best = INF; auto& distA = dist[a]; auto& distB = dist[b]; for (int G = n; G > 0; G--) { size_t limit = firsts[G].size(); const vector<int>& f = firsts[G]; const vector<int>& s = seconds[G]; for (size_t idx = 0; idx < limit; ++idx) { int w1 = f[idx]; int w2 = s[idx]; int dAw1 = distA[w1]; int dBw1 = distB[w1]; int dAw2 = distA[w2]; int dBw2 = distB[w2]; int pl = turboMin(dAw1, dBw1) + turboMin(dAw2, dBw2); if (pl > maxTeleLen) { maxTeleLen = pl; if (maxTeleLen >= curBest) { return best; } } } if (maxTeleLen >= best) { return best; } best = max(maxTeleLen, G - 1); } return maxTeleLen; } int judge(int n, int a, int b) { int mx = 0; for (int i = 0; i < n; i++) { for (int j = i + 1; j < n ; j++) { mx = max(mx, min( dist[i][j], min(dist[a][i], dist[b][i]) + min(dist[a][j], dist[b][j]))); } } return mx; } pair<int, int> proposeNear(int n, int a, int b) { vector<pair<int, int>> props; for (int i = 0; i < n; i++) { if (dist[i][a] == 1) { props.emplace_back(i, b); } if (dist[i][b] == 1) { props.emplace_back(a, i); } } return props[rand() % props.size()]; } int anneal(int n) { int global_min = n; for (int k = 0; k < 4; k++) { float T = 1; float T_min = 0.003; float alpha = 0.9; int numIterations = 100; int a = rand() % n; int b = rand() % n; int sol_val = judge(n, a, b); global_min = min(global_min, sol_val); while (T > T_min) { for (int iter = 0; iter < numIterations; iter++) { if (sol_val < global_min) { global_min = sol_val; } pair<int, int> next = proposeNear(n, a, b); int prop_a = next.first; int prop_b = next.second; int new_min = judge(n, prop_a, prop_b); float acceptProbab = exp((sol_val - new_min) / T); if (acceptProbab > (float) rand() / RAND_MAX) { a = prop_a; b = prop_b; sol_val = new_min; } } T *= alpha; //printf("TEMP %f, wyn %d\n", T, global_min); } } return global_min; } int brutuj(int n) { int wyn = n; for (int i = 0; i < n; i++) { perm[i] = i; } random_shuffle(perm, perm + n); for (int i = 0; i < n; i++) { random_shuffle(perm + i + 1, perm + n); for (int j = i + 1; j < n; j++) { wyn = min(wyn, best_for_2(n, perm[i], perm[j], wyn)); } } return wyn; } int runSingleTest() { int n; scanf("%d", &n); for (int i = 0; i < n; i++) { scanf("%s", adj[i]); } calcDist(n); int wyn = n <= BRUT_THRESHOLD ? brutuj(n) : anneal(n); return wyn; } int main() { srand(time(NULL)); int T; scanf("%d", &T); for (int i = 0; i < T; i++) { int res = runSingleTest(); printf("%d\n", res); } }
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 | #include <cstdio> #include <algorithm> #include <vector> #include <ctime> #include <cmath> using namespace std; const int MAX_SIZE = 402; const int INF = 100000; const int BRUT_THRESHOLD = 200; char adj[MAX_SIZE][MAX_SIZE]; int dist[MAX_SIZE][MAX_SIZE]; int perm[MAX_SIZE]; vector<pair<int,int>> paths_of_length[MAX_SIZE]; vector<int> firsts[MAX_SIZE]; vector<int> seconds[MAX_SIZE]; inline int turboMin(int a, int b) { return b + ((a-b) & (a-b)>>31); } inline int turboMax(int a, int b) { return a - ((a-b) & (a-b)>>31); } void calcDist(int n) { for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { if (i == j) { dist[i][j] = 0; } else if (adj[i][j] == '1') { dist[i][j] = 1; } else { dist[i][j] = INF; } } } for (int k = 0; k < n; k++) { for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { if (dist[i][j] > dist[i][k] + dist[k][j]) { dist[i][j] = dist[i][k] + dist[k][j]; } } } } for (int i = 0; i <= n; i++) { paths_of_length[i].clear(); } for (int i = 0; i < n; i++) { for (int j = i + 1; j < n; j++) { paths_of_length[dist[i][j]].emplace_back(i, j); } } for (int i = 0; i <= n; i++) { random_shuffle(paths_of_length[i].begin(), paths_of_length[i].end()); } for (int i = 0; i <= n; i++) { firsts[i].resize(paths_of_length[i].size()); seconds[i].resize(paths_of_length[i].size()); for (size_t j = 0; j < paths_of_length[i].size(); j++) { firsts[i][j] = paths_of_length[i][j].first; seconds[i][j] = paths_of_length[i][j].second; } } } int best_for_2(int n, int a, int b, int curBest) { int maxTeleLen = 0; int best = INF; auto& distA = dist[a]; auto& distB = dist[b]; for (int G = n; G > 0; G--) { size_t limit = firsts[G].size(); const vector<int>& f = firsts[G]; const vector<int>& s = seconds[G]; for (size_t idx = 0; idx < limit; ++idx) { int w1 = f[idx]; int w2 = s[idx]; int dAw1 = distA[w1]; int dBw1 = distB[w1]; int dAw2 = distA[w2]; int dBw2 = distB[w2]; int pl = turboMin(dAw1, dBw1) + turboMin(dAw2, dBw2); if (pl > maxTeleLen) { maxTeleLen = pl; if (maxTeleLen >= curBest) { return best; } } } if (maxTeleLen >= best) { return best; } best = max(maxTeleLen, G - 1); } return maxTeleLen; } int judge(int n, int a, int b) { int mx = 0; for (int i = 0; i < n; i++) { for (int j = i + 1; j < n ; j++) { mx = max(mx, min( dist[i][j], min(dist[a][i], dist[b][i]) + min(dist[a][j], dist[b][j]))); } } return mx; } pair<int, int> proposeNear(int n, int a, int b) { vector<pair<int, int>> props; for (int i = 0; i < n; i++) { if (dist[i][a] == 1) { props.emplace_back(i, b); } if (dist[i][b] == 1) { props.emplace_back(a, i); } } return props[rand() % props.size()]; } int anneal(int n) { int global_min = n; for (int k = 0; k < 4; k++) { float T = 1; float T_min = 0.003; float alpha = 0.9; int numIterations = 100; int a = rand() % n; int b = rand() % n; int sol_val = judge(n, a, b); global_min = min(global_min, sol_val); while (T > T_min) { for (int iter = 0; iter < numIterations; iter++) { if (sol_val < global_min) { global_min = sol_val; } pair<int, int> next = proposeNear(n, a, b); int prop_a = next.first; int prop_b = next.second; int new_min = judge(n, prop_a, prop_b); float acceptProbab = exp((sol_val - new_min) / T); if (acceptProbab > (float) rand() / RAND_MAX) { a = prop_a; b = prop_b; sol_val = new_min; } } T *= alpha; //printf("TEMP %f, wyn %d\n", T, global_min); } } return global_min; } int brutuj(int n) { int wyn = n; for (int i = 0; i < n; i++) { perm[i] = i; } random_shuffle(perm, perm + n); for (int i = 0; i < n; i++) { random_shuffle(perm + i + 1, perm + n); for (int j = i + 1; j < n; j++) { wyn = min(wyn, best_for_2(n, perm[i], perm[j], wyn)); } } return wyn; } int runSingleTest() { int n; scanf("%d", &n); for (int i = 0; i < n; i++) { scanf("%s", adj[i]); } calcDist(n); int wyn = n <= BRUT_THRESHOLD ? brutuj(n) : anneal(n); return wyn; } int main() { srand(time(NULL)); int T; scanf("%d", &T); for (int i = 0; i < T; i++) { int res = runSingleTest(); printf("%d\n", res); } } |