Add kruscal algorithm

Author: roytravel

99. others/Data Structure/탐색 알고리즘/bellman_ford.py 99. others/Data Structure/탐색 알고리즘/최단 거리/bellman_ford.py

@@ -0,0 +1,52 @@
+"""
+6 8
+1 2 7
+1 3 5
+2 3 2
+2 4 6
+2 5 9
+3 6 1
+4 5 11
+5 6 12
+"""
+import sys
+input = sys.stdin.readline
+
+def find_parent(parent, x):
+    """ 부모 노드를 찾기 위해 재귀 수행"""
+    if parent[x] != x:
+        parent[x] = find_parent(parent, parent[x])
+    return parent[x]
+
+def union_parent(parent, a, b):
+    """ 부모 노드 비교(사이클 판별)후 부모 노드 업데이트 """
+    a = find_parent(parent, a)
+    b = find_parent(parent, b)
+    if a < b:
+        parent[b] = a
+    else:
+        parent[a] = b
+
+if __name__ == "__main__":
+    V, E = map(int, input().split()) # make graph
+    graph = [] 
+    for _ in range(E):
+        a, b, cost = map(int, input().split())
+        graph.append([a, b, cost])
+    graph.sort(key=lambda x:x[2])
+
+
+    parent = [0] * (V+1) # make parent table
+    for i in range(1, V+1):
+        parent[i] = i
+
+    costs, mst = 0, [] # get mst
+    for i in range(E):
+        a, b, cost = graph[i]
+        if find_parent(parent, a) != find_parent(parent, b):
+            union_parent(parent, a, b)
+            mst.append((a, b))
+            costs += cost
+
+    print (mst)
+    print (costs)