#include <iostream> #define EACH_CITY(iter) (iter = 1; iter <= n; iter++) using namespace std; typedef unsigned int INT; const INT N = 200000; const INT M = 200000; const INT D = 200000; struct city; struct connection; struct city { bool removed; INT id; INT group_id; INT connections_count; INT connectivity; connection *connections; void notify_adjacent_city_removal(); void check(); void remove(); INT mark_city_group(INT gid, INT acc = 0); bool can_mark(); }; struct connection { city * from; city * to; }; INT n, m, d; city cities[N+1]; connection *connections; void inline city::notify_adjacent_city_removal() { connectivity--; check(); } void inline city::check() { if (!removed && connectivity < d) remove(); } void city::remove() { INT i; removed = true; for (i = 0; i < connections_count; i++) { connections[i].to->notify_adjacent_city_removal(); } } INT city::mark_city_group(INT gid, INT acc) { INT i; group_id = gid; acc++; for (i = 0; i < connections_count; i++) { if (connections[i].to->can_mark()) { acc += connections[i].to->mark_city_group(gid); } } return acc; } bool inline city::can_mark() { return (!removed && group_id == 0); } int inline cmp_connections(const void * a, const void * b) { return (((connection*) a)->from - ((connection*) b)->from); } void read_input() { INT i, a, b; INT p, q; city *ct; cin >> n >> m >> d; connections = new connection[m * 2]; for (i = 0; i < m; i++) { cin >> p >> q; connections[2 * i].from = &cities[p]; connections[2 * i].to = &cities[q]; connections[2 * i + 1].from = &cities[q]; connections[2 * i + 1].to = &cities[p]; } qsort(connections, 2 * m, sizeof(connection), cmp_connections); a = 0; for EACH_CITY(i) { ct = &cities[i]; while (connections[a].from != ct && a < 2 * m) a++; b = a; while (connections[b].from == ct && b < 2 * m) b++; ct->id = i; ct->connections = &connections[a]; ct->connections_count = ct->connectivity = b - a; a = b; } } void write_successful_output(INT k, INT gid) { INT i; cout << k << endl; for EACH_CITY(i) { if (cities[i].group_id == gid) { cout << cities[i].id << " "; } } } void write_failure_output() { cout << "NIE"; } void initial_check() { INT i; for EACH_CITY(i) cities[i].check(); } void find_best() { INT i, v; INT best_v = 0, best_i = 0; for EACH_CITY(i) { if (cities[i].can_mark()) { v = cities[i].mark_city_group(i); if (v > best_v) { best_v = v; best_i = i; }; } } if (best_v > 0) { write_successful_output(best_v, best_i); } else { write_failure_output(); } } int main(int argc, char** argv) { read_input(); initial_check(); find_best(); 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 | #include <iostream> #define EACH_CITY(iter) (iter = 1; iter <= n; iter++) using namespace std; typedef unsigned int INT; const INT N = 200000; const INT M = 200000; const INT D = 200000; struct city; struct connection; struct city { bool removed; INT id; INT group_id; INT connections_count; INT connectivity; connection *connections; void notify_adjacent_city_removal(); void check(); void remove(); INT mark_city_group(INT gid, INT acc = 0); bool can_mark(); }; struct connection { city * from; city * to; }; INT n, m, d; city cities[N+1]; connection *connections; void inline city::notify_adjacent_city_removal() { connectivity--; check(); } void inline city::check() { if (!removed && connectivity < d) remove(); } void city::remove() { INT i; removed = true; for (i = 0; i < connections_count; i++) { connections[i].to->notify_adjacent_city_removal(); } } INT city::mark_city_group(INT gid, INT acc) { INT i; group_id = gid; acc++; for (i = 0; i < connections_count; i++) { if (connections[i].to->can_mark()) { acc += connections[i].to->mark_city_group(gid); } } return acc; } bool inline city::can_mark() { return (!removed && group_id == 0); } int inline cmp_connections(const void * a, const void * b) { return (((connection*) a)->from - ((connection*) b)->from); } void read_input() { INT i, a, b; INT p, q; city *ct; cin >> n >> m >> d; connections = new connection[m * 2]; for (i = 0; i < m; i++) { cin >> p >> q; connections[2 * i].from = &cities[p]; connections[2 * i].to = &cities[q]; connections[2 * i + 1].from = &cities[q]; connections[2 * i + 1].to = &cities[p]; } qsort(connections, 2 * m, sizeof(connection), cmp_connections); a = 0; for EACH_CITY(i) { ct = &cities[i]; while (connections[a].from != ct && a < 2 * m) a++; b = a; while (connections[b].from == ct && b < 2 * m) b++; ct->id = i; ct->connections = &connections[a]; ct->connections_count = ct->connectivity = b - a; a = b; } } void write_successful_output(INT k, INT gid) { INT i; cout << k << endl; for EACH_CITY(i) { if (cities[i].group_id == gid) { cout << cities[i].id << " "; } } } void write_failure_output() { cout << "NIE"; } void initial_check() { INT i; for EACH_CITY(i) cities[i].check(); } void find_best() { INT i, v; INT best_v = 0, best_i = 0; for EACH_CITY(i) { if (cities[i].can_mark()) { v = cities[i].mark_city_group(i); if (v > best_v) { best_v = v; best_i = i; }; } } if (best_v > 0) { write_successful_output(best_v, best_i); } else { write_failure_output(); } } int main(int argc, char** argv) { read_input(); initial_check(); find_best(); return 0; } |