create dev channel

zeta/py/completed/1504.py

@@ -0,0 +1,47 @@
+import heapq
+import sys
+
+input = sys.stdin.readline
+
+
+def dijkstra(N, E, start) -> list[int]:
+    heap = []
+    distance = [10 ** 9 + 1 for _ in range(N + 1)]
+    distance[start] = 0
+    heapq.heappush(heap, (0, start,))
+    while heap:
+        cost, now, = heapq.heappop(heap)
+        if distance[now] < cost:
+            continue
+
+        for new, weight in E[now]:
+            new_cost = cost + weight
+            if new_cost < distance[new]:
+                distance[new] = new_cost
+                heapq.heappush(heap, (new_cost, new))
+
+    return distance
+
+
+def solve(N, E, v1, v2) -> int:
+    heap = []
+    distance_from_v1 = dijkstra(N, E, v1, )
+    distance_from_v2 = dijkstra(N, E, v2, )
+    ret = min(
+        (sum((distance_from_v1[1], distance_from_v1[v2], distance_from_v2[N])),
+         sum((distance_from_v2[1], distance_from_v2[v1], distance_from_v1[N])))
+    )
+    return ret if ret < 10 ** 9 + 1 else -1
+
+
+if __name__ == '__main__':
+    N, e = map(int, input().split())
+    E = {}
+    for i in range(1, N + 1):
+        E[i] = []
+    for _ in range(e):
+        a, b, c = map(int, input().split())
+        E[a].append((b, c))
+        E[b].append((a, c))
+    v1, v2 = map(int, input().split())
+    print(solve(N, E, v1, v2))