최단경로 solved

alstjr7437/그래프/최단경로.py

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+from heapq import *
+import sys
+
+input = sys.stdin.readline
+
+v, e = map(int, input().split())
+k = int(input())
+
+# 그래프 만들기
+graph = [[] for _ in range(v + 1)]
+for _ in range(e):
+    a, b, c = map(int, input().split())
+    graph[a].append((c, b))  
+
+# 결과 저장할 변수 만들기
+heap = []
+result = [int(1e9)] * (v + 1)
+
+# k 넣기
+result[k] = 0
+heappush(heap, (0, k))  
+
+# 다익스트라 돌리기
+while heap:
+    weight, now = heappop(heap)  
+    # print(weight,now, heap, result)
+    if result[now] < weight:
+        continue
+    for next_weight, next_node in graph[now]:
+        total_weight = weight + next_weight
+        if total_weight < result[next_node]:
+            result[next_node] = total_weight
+            heappush(heap, (total_weight, next_node))
+
+# 결과 출력하기
+for i in range(1, v + 1):
+    if result[i] == int(1e9):
+        print("INF")
+    else:
+        print(result[i])