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 #include #include #include #include #include #include #include using namespace std; typedef vector VI; typedef long long LL; typedef pair PII; #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 #define MP make_pair #define INF 1000000001 struct Rect { PII x, y; // x.ST < x.ND && y.ST < y.ND Rect(int x1 = 0, int x2 = 0, int y1 = 0, int y2 = 0) : x(x1, x2), y(y1, y2) { } bool operator<(const Rect& r) const { return (x != r.x ? x < r.x : y < r.y); } }; struct ARect { PII x, y; mutable int cnt; ARect(int y1 = 0, int y2 = 0, int x1 = 0, int x2 = 0, int c = 0) : x(x1, x2), y(y1, y2), cnt(c) { } bool operator<(const ARect& r) const { return y.ST < r.y.ST; } }; struct IVal { int x; PII y; int t; // 0 - left 1 - right edge int r; // Rect IVal(int _x = 0, int y1 = 0, int y2 = 0, int _t = 0, int _r = 0) : x(_x), y(y1, y2), t(_t), r(_r) { } bool operator<(const IVal& i) const { if (x != i.x) return x < i.x; if (t != i.t) return t > i.t; return y < i.y; } }; PII MinMax(const PII& p0, const PII& p1) { return MP(min(p0.ST, p1.ST), max(p0.ND, p1.ND)); } void AddIVal(set& s, const IVal& i, const Rect& r) { ARect a(i.y.ST, i.y.ND, r.x.ST, r.x.ND, 1); auto v = s.upper_bound(ARect(i.y.ST)); if (!s.empty() && v != s.begin()) { auto w = v; --w; if (a.y.ST < w->y.ND) v = w; } while (v != s.end() && v->y.ST < a.y.ND) { a.x = MinMax(a.x, v->x); a.y = MinMax(a.y, v->y); a.cnt += v->cnt; s.erase(v++); } s.insert(a); } void DelIVal(set& s, const IVal& i, vector* vr, vector* vi) { auto v = s.lower_bound(ARect(i.y.ND)); assert(v != s.begin()); --v; if (--v->cnt == 0) { int id = SIZE(*vr); //Rect r(-v->x.ND, -v->x.ST, -v->y.ND, -v->y.ST); Rect r(v->y.ST, v->y.ND, -v->x.ND, -v->x.ST); vr->PB(r); vi->PB(IVal(r.x.ST, r.y.ST, r.y.ND, 0, id)); vi->PB(IVal(r.x.ND, r.y.ST, r.y.ND, 1, id)); s.erase(v); } } int main() { vector R[2], *pr = &R[0], *cr = &R[1]; vector I[2], *pi = &I[0], *ci = &I[1]; int n, x1, x2, y1, y2; scanf("%d\n", &n); REP(i, n) { scanf("%d %d %d %d\n", &x1, &x2, &y1, &y2); pr->PB(Rect(x1, x2, y1, y2)); pi->PB(IVal(x1, y1, y2, 0, i)); pi->PB(IVal(x2, y1, y2, 1, i)); } REP(i, 4) { sort(ALL(*pi)); set s; cr->clear(); ci->clear(); FOREACH(it, *pi) { if (!it->t) AddIVal(s, *it, (*pr)[it->r]); else DelIVal(s, *it, cr, ci); } assert(s.empty()); swap(pr, cr); swap(pi, ci); } sort(ALL(*pr)); printf("%d\n", SIZE(*pr)); FOREACH(it, *pr) printf("%d %d %d %d\n", it->x.ST, it->x.ND, it->y.ST, it->y.ND); return 0; }