并查集+计算几何。
1 /* 1558 */ 2 #include <cstdio> 3 #include <cstring> 4 #include <cstdlib> 5 6 #define MAXN 1005 7 8 typedef struct { 9 double x, y; 10 } Point_t; 11 12 typedef struct { 13 Point_t b, e; 14 } Seg_t; 15 16 Seg_t segs[MAXN]; 17 int pre[MAXN]; 18 int ans[MAXN]; 19 20 int max(int a, int b) { 21 return a>b ? a:b; 22 } 23 24 int min(int a, int b) { 25 return a<b ? a:b; 26 } 27 28 double direction(Point_t p0, Point_t p1, Point_t p2) { 29 return (p1.x-p0.x)*(p2.y-p0.y) - (p1.y-p0.y)*(p2.x-p0.x); 30 } 31 32 bool onSegment(Point_t p0, Point_t p1, Point_t p2) { 33 if ( (min(p0.x, p1.x)<=p2.x && p2.x<=max(p0.x, p1.x)) && 34 (min(p0.y, p1.y)<=p2.y && p2.y<=max(p0.y, p1.y)) ) 35 return true; 36 return false; 37 } 38 39 bool intersect(Seg_t x, Seg_t y) { 40 Point_t p1 = x.b, p2 = x.e, p3 = y.b, p4 = y.e; 41 double d1 = direction(p3, p4, p1); 42 double d2 = direction(p3, p4, p2); 43 double d3 = direction(p1, p2, p3); 44 double d4 = direction(p1, p2, p4); 45 if ( ((d1>0 && d2<0) || (d1<0 && d2>0)) && 46 ((d3>0 && d4<0) || (d3<0 && d4>0)) ) 47 return true; 48 else if (d1==0 && onSegment(p3, p4, p1)) 49 return true; 50 else if (d2==0 && onSegment(p3, p4, p2)) 51 return true; 52 else if (d3==0 && onSegment(p1, p2, p3)) 53 return true; 54 else if (d4==0 && onSegment(p1, p2, p4)) 55 return true; 56 else 57 return false; 58 } 59 60 int find(int x) { 61 if (x == pre[x]) 62 return x; 63 pre[x] = find(pre[x]); 64 return pre[x]; 65 } 66 67 void merge(int x, int y) { 68 int fx = find(x); 69 int fy = find(y); 70 if (fx != fy) { 71 pre[fy] = fx; 72 ans[fx] += ans[fy]; 73 ans[fy] = 0; 74 } 75 } 76 77 int main() { 78 int t, n, m; 79 int i, j, k; 80 char cmd[3]; 81 82 #ifndef ONLINE_JUDGE 83 freopen("data.in", "r", stdin); 84 #endif 85 86 scanf("%d", &t); 87 while (t--) { 88 scanf("%d", &n); 89 for (i=1; i<=n; ++i) { 90 pre[i] = i; 91 ans[i] = 1; 92 } 93 m = 1; 94 while (n--) { 95 scanf("%s", cmd); 96 if (cmd[0] == 'P') { 97 scanf("%lf%lf%lf%lf", &segs[m].b.x, &segs[m].b.y, &segs[m].e.x, &segs[m].e.y); 98 for (i=1; i<m; ++i) { 99 if (intersect(segs[i], segs[m])) 100 merge(i, m); 101 } 102 ++m; 103 } else { 104 scanf("%d", &j); 105 k = find(j); 106 printf("%d ", ans[k]); 107 } 108 } 109 if (t) 110 printf(" "); 111 } 112 113 return 0; 114 }