#include <cstdio> #include <iostream> #include <algorithm> #include <string> #include <vector> #include <utility> #include <set> using namespace std; typedef vector<int> VI; typedef long long LL; #define FOR(x, b, e) for (int x = b; x <= (e); ++x) #define FORD(x, b, e) for (int x = b; x >= (e); --x) #define REP(x, n) for (int x = 0; x < (n); ++x) #define VAR(v, n) __typeof(n) v = (n) #define ALL(c) (c).begin(), (c).end() #define SIZE(x) ((int)(x).size()) #define FOREACH(i, c) for (VAR(i, (c).begin()); i != (c).end(); ++i) #define PB push_back #define ST first #define ND second int n, m, d; int heapIdx[200001]; struct City { int nr; int sss; set<City*> roads; City() : nr(-1), sss(-1) {} }; City* cities[200001]; void heap_down(int n, int i) { int left = i * 2, right = i * 2 + 1; int smallest = i; if (left <= n && cities[left]->roads.size() < cities[smallest]->roads.size()) { smallest = left; } if (right <= n && cities[right]->roads.size() < cities[smallest]->roads.size()) { smallest = right; } if (i != smallest) { City* tmp = cities[i]; cities[i] = cities[smallest]; cities[smallest] = tmp; heapIdx[cities[i]->nr] = i; heapIdx[cities[smallest]->nr] = smallest; heap_down(n, smallest); } } void heap_up(int n, int i) { int parent = i / 2; if (parent > 0 && cities[parent]->roads.size() > cities[i]->roads.size()) { City* tmp = cities[i]; cities[i] = cities[parent]; cities[parent] = tmp; heapIdx[cities[i]->nr] = i; heapIdx[cities[parent]->nr] = parent; heap_up(n, parent); } } void heap_pop(int n) { heapIdx[cities[1]->nr] = -1; cities[1] = cities[n]; heapIdx[cities[1]->nr] = 1; heap_down(n - 1, 1); } void build_heap(int n) { FORD(i, n, 1) heap_down(n, i); } int dfs(int i, int sss) { City* c = cities[i]; if (c->sss != -1) return 0; c->sss = sss; int sum = 1; FOREACH (r, c->roads) sum += dfs(heapIdx[(*r)->nr], sss); return sum; } int main() { int N; scanf("%d %d %d", &n, &m, &d); N = n; REP (i, n + 1) { cities[i] = new City; cities[i]->nr = i; heapIdx[i] = i; } int from, to; REP (i, m) { scanf("%d %d", &from, &to); cities[from]->roads.insert(cities[to]); cities[to]->roads.insert(cities[from]); } build_heap(n); while (n > 0 && cities[1]->roads.size() < d) { City* top = cities[1]; heap_pop(n--); FOREACH (i, top->roads) { int DEBUG = (*i)->roads.erase(top); heap_up(n, heapIdx[(*i)->nr]); } delete top; } if (n == 0) printf("NIE\n"); else { int max = 0; int sss = -1; FOR(i, 1, n) { int tmp = dfs(i, i); if (tmp > max) { sss = i; max = tmp; } } printf("%d\n", max); FOR(i, 1, N) { if (heapIdx[i] != -1 && cities[heapIdx[i]]->sss == sss) { printf("%d ", cities[heapIdx[i]]->nr); } } printf("\n"); } FOR(i, 1, n) delete cities[i]; 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 | #include <cstdio> #include <iostream> #include <algorithm> #include <string> #include <vector> #include <utility> #include <set> using namespace std; typedef vector<int> VI; typedef long long LL; #define FOR(x, b, e) for (int x = b; x <= (e); ++x) #define FORD(x, b, e) for (int x = b; x >= (e); --x) #define REP(x, n) for (int x = 0; x < (n); ++x) #define VAR(v, n) __typeof(n) v = (n) #define ALL(c) (c).begin(), (c).end() #define SIZE(x) ((int)(x).size()) #define FOREACH(i, c) for (VAR(i, (c).begin()); i != (c).end(); ++i) #define PB push_back #define ST first #define ND second int n, m, d; int heapIdx[200001]; struct City { int nr; int sss; set<City*> roads; City() : nr(-1), sss(-1) {} }; City* cities[200001]; void heap_down(int n, int i) { int left = i * 2, right = i * 2 + 1; int smallest = i; if (left <= n && cities[left]->roads.size() < cities[smallest]->roads.size()) { smallest = left; } if (right <= n && cities[right]->roads.size() < cities[smallest]->roads.size()) { smallest = right; } if (i != smallest) { City* tmp = cities[i]; cities[i] = cities[smallest]; cities[smallest] = tmp; heapIdx[cities[i]->nr] = i; heapIdx[cities[smallest]->nr] = smallest; heap_down(n, smallest); } } void heap_up(int n, int i) { int parent = i / 2; if (parent > 0 && cities[parent]->roads.size() > cities[i]->roads.size()) { City* tmp = cities[i]; cities[i] = cities[parent]; cities[parent] = tmp; heapIdx[cities[i]->nr] = i; heapIdx[cities[parent]->nr] = parent; heap_up(n, parent); } } void heap_pop(int n) { heapIdx[cities[1]->nr] = -1; cities[1] = cities[n]; heapIdx[cities[1]->nr] = 1; heap_down(n - 1, 1); } void build_heap(int n) { FORD(i, n, 1) heap_down(n, i); } int dfs(int i, int sss) { City* c = cities[i]; if (c->sss != -1) return 0; c->sss = sss; int sum = 1; FOREACH (r, c->roads) sum += dfs(heapIdx[(*r)->nr], sss); return sum; } int main() { int N; scanf("%d %d %d", &n, &m, &d); N = n; REP (i, n + 1) { cities[i] = new City; cities[i]->nr = i; heapIdx[i] = i; } int from, to; REP (i, m) { scanf("%d %d", &from, &to); cities[from]->roads.insert(cities[to]); cities[to]->roads.insert(cities[from]); } build_heap(n); while (n > 0 && cities[1]->roads.size() < d) { City* top = cities[1]; heap_pop(n--); FOREACH (i, top->roads) { int DEBUG = (*i)->roads.erase(top); heap_up(n, heapIdx[(*i)->nr]); } delete top; } if (n == 0) printf("NIE\n"); else { int max = 0; int sss = -1; FOR(i, 1, n) { int tmp = dfs(i, i); if (tmp > max) { sss = i; max = tmp; } } printf("%d\n", max); FOR(i, 1, N) { if (heapIdx[i] != -1 && cities[heapIdx[i]]->sss == sss) { printf("%d ", cities[heapIdx[i]]->nr); } } printf("\n"); } FOR(i, 1, n) delete cities[i]; return 0; } |