'''
算法思路
在克鲁斯卡尔构建最小生成树增加长度为w的一条边连接两个连通分量的同时,将两个连通分量
中的点对全部用w+1的权值的边连接起来,最后的完全图的总边权和就是最小的, 克鲁斯卡尔
算法迭代过程中累加长度是w+1的边权即可
'''
class MergeSetExt:
def __init__(self, max_key_val = 0, trans_key_func=None):
if trans_key_func is not None and max_key_val > 0:
# 如果能够提供转换key的回调,并查集内部用线性表存储
self.trans_key_callback = trans_key_func
self.m = [-1 for _ in range(max_key_val+1)]
self.__root2cluster_size = [0 for _ in range(max_key_val+1)]
else:
# 如果不能提供转换key的回调,并查集内部用hash表存储
self.trans_key_callback = None
self.m = {}
self.__root2cluster_size = {}
self.__root_cnt = 0
def getRoot(self, node):
buf = []
root = self.trans_key_callback(node) if self.trans_key_callback else node
while self.m[root] != root:
buf.append(root)
root = self.m[root]
for key in buf:
self.m[key] = root
return root
def merge(self, a, b):
orig_a, orig_b = a, b
if self.trans_key_callback:
a, b = self.trans_key_callback(a), self.trans_key_callback(b)
for node in [a, b]:
if (self.trans_key_callback is None and node not in self.m) or (self.trans_key_callback is not None and self.m[node] == -1):
self.m[node] = node
self.__root2cluster_size[node] = 1
self.__root_cnt += 1
root1 = self.getRoot(orig_a)
root2 = self.getRoot(orig_b)
if root1 != root2:
self.m[root1] = root2
self.__root2cluster_size[root2] += self.__root2cluster_size[root1]
if self.trans_key_callback:
self.__root2cluster_size[root1] = 0
else:
self.__root2cluster_size.pop(root1)
self.__root_cnt -= 1
# 根据根节点的数值获取其所在的簇的大小
def getClusterSize(self, root):
return self.__root2cluster_size[root]
def isInSameSet(self, a, b):
if a == b:
return True
orig_a, orig_b = a, b
if self.trans_key_callback:
a, b = self.trans_key_callback(a), self.trans_key_callback(b)
for node in [a, b]:
if self.m[node] == -1:
return False
else:
for node in [orig_a, orig_b]:
if node not in self.m:
return False
return self.getRoot(orig_a) == self.getRoot(orig_b)
def getRootNum(self):
return self.__root_cnt
def getClusters(self):
rec = {}
if self.trans_key_callback is None:
for node in self.m:
root = self.getRoot(node)
if root not in rec:
rec[root] = []
rec[root].append(node)
else:
for node in range(len(self.m)):
if self.m[node] == -1:
continue
root = self.getRoot(node)
if root not in rec:
rec[root] = []
rec[root].append(node)
return [nodes for nodes in rec.values()]
def getMinSpanTreeKruscal(edges, node_num):
if len(edges) == 0:
return [None, None]
edge_list = [(w, a, b) for a, b, w in edges]
edge_list.sort()
merge_set = MergeSetExt(max_key_val=node_num, trans_key_func= lambda x: x)
for node in range(1, node_num+1):
merge_set.merge(node, node)
sum = 0
edge_cnt = 0
for w, a, b in edge_list:
if merge_set.isInSameSet(a, b):
continue
# 获取a, b所在连通分量的所有节点,两个连通分量之间的点出了a, b以外全部
# 连接起来,边权是w+1
root_a, root_b = merge_set.getRoot(a), merge_set.getRoot(b)
cnt1, cnt2 = merge_set.getClusterSize(root_a), merge_set.getClusterSize(root_b)
sum += (cnt1 * cnt2 - 1) * (w+1)
merge_set.merge(a, b)
edge_cnt += 1
if edge_cnt == node_num - 1:
break
return sum
t = int(input())
for _ in range(t):
n = int(input())
edges = []
for i in range(n-1):
a, b, w = map(int, input().split())
edges.append((a,b,w))
print(getMinSpanTreeKruscal(edges, node_num=n))