2024-08-28 solved

alstjr7437/다익스트라/파티.py

@@ -0,0 +1,38 @@
+from collections import deque 
+import sys
+
+input = sys.stdin.readline
+INF = int(1e9)
+
+N, M, X = map(int, input().split())
+
+graph = [[] for _ in range(N+1)]
+
+for _ in range(M):
+    start, target, dist = map(int, input().split())
+    graph[start].append((target, dist))
+
+def dijkstra(root):
+    queue = deque()
+    distance = [INF] * (N + 1)
+
+    distance[root] = 0
+    queue.append((root, 0))
+    while queue:
+        now, dist = queue.popleft()
+
+        for target, cost in graph[now]:
+            target_cost = dist + cost
+
+            if distance[target] > target_cost:
+                distance[target] = target_cost
+                queue.append((target, target_cost))
+    return distance
+
+result = []
+for i in range(1, N+1):
+    go = dijkstra(i)[X]
+    back = dijkstra(X)[i]
+    result.append(go+back)
+
+print(max(result))