34-alstjr7437 (#241)

alstjr7437/README.md

@@ -34,4 +34,5 @@
 | 30차시 | 2024.06.19 |  구현  | <a href="https://www.acmicpc.net/problem/1475">방 번호</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/211 |
 | 31차시 | 2024.06.19 |  BFS  | <a href="https://school.programmers.co.kr/learn/courses/30/lessons/1844">게임 맵 최단거리</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/218 |
 | 32차시 | 2024.08.15 |  투 포인터  | <a href="https://www.acmicpc.net/problem/30804">과일 탕후루</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/230 |
-| 33차시 | 2024.08.21 |  BFS  | <a href="https://www.acmicpc.net/problem/9019">DSLR</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/236 |
+| 33차시 | 2024.08.21 |  BFS  | <a href="https://www.acmicpc.net/problem/9019">DSLR</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/236 |
+| 34차시 | 2024.08.28 |  다익스트라  | <a href="https://www.acmicpc.net/problem/1238">파티</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/241 |

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))