leetcode: finished #743

content/leetcode/2024/2.md

@@ -3,6 +3,41 @@ title: 2024.2
 draft: false
 ---
 
+# 2024.2.2
+
+```python
+#
+# @lc app=leetcode.cn id=743 lang=python3
+#
+# [743] 网络延迟时间
+#
+
+# @lc code=start
+class Solution:
+    def networkDelayTime(self, times: List[List[int]], n: int, k: int) -> int:
+        import heapq
+
+        graph = [[] for _ in range(n + 1)]
+        for u, v, w in times:
+            graph[u].append((v, w))
+        dist = [float("inf")] * (n + 1)
+        dist[k] = 0
+        heap = [(0, k)]
+        while heap:
+            d, u = heapq.heappop(heap)
+            if d > dist[u]:
+                continue
+            for v, w in graph[u]:
+                if dist[v] > d + w:
+                    dist[v] = d + w
+                    heapq.heappush(heap, (dist[v], v))
+        res = max(dist[1:])
+        return res if res < float("inf") else -1
+
+
+# @lc code=end
+```
+
 # 2024.2.1
 
 ```python