#include #include #define MAXN 1005 typedef long long ll; int fa[MAXN], rank[MAXN]; ll X[MAXN], Y[MAXN], Z[MAXN]; inline bool next_to(ll x1, ll y1, ll z1, ll x2, ll y2, ll z2, ll r) { return (x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2) + (z1 - z2) * (z1 - z2) <= 4 * r * r; //判断两个空洞是否相交或相切 } inline void init(int n) { for (int i = 1; i <= n; ++i) { fa[i] = i; rank[i] = 1; } } int find(int x) { return x == fa[x] ? x : (fa[x] = find(fa[x])); } inline void merge(int i, int j) { int x = find(i), y = find(j); if (rank[x] <= rank[y]) fa[x] = y; else fa[y] = x; if (rank[x] == rank[y] && x != y) rank[y]++; } int main() { int T, n, h; ll r; scanf("%d", &T); for (int I = 0; I < T; ++I) { memset(X, 0, sizeof(X)); memset(Y, 0, sizeof(Y)); memset(Z, 0, sizeof(Z)); scanf("%d%d%lld", &n, &h, &r); init(n); fa[1001] = 1001; //用1001代表底部 fa[1002] = 1002; //用1002代表顶部 for (int i = 1; i <= n; ++i) scanf("%lld%lld%lld", X + i, Y + i, Z + i); for (int i = 1; i <= n; ++i) { if (Z[i] <= r) merge(i, 1001); //与底部接触的空洞与底部合并 if (Z[i] + r >= h) merge(i, 1002); //与顶部接触的空洞与顶部合并 } for (int i = 1; i <= n; ++i) { for (int j = i + 1; j <= n; ++j) { if (next_to(X[i], Y[i], Z[i], X[j], Y[j], Z[j], r)) merge(i, j); //遍历所有空洞,合并相交或相切的球 } } printf("%s\n", find(1001) == find(1002) ? "Yes" : "No"); } return 0; }