2025-01-09

tgyuuAn/README.md

@@ -88,4 +88,5 @@
 | 82차시 | 2024.11.22 |  희소 배열  | <a href="https://www.acmicpc.net/problem/17435">합성함수와 쿼리</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/257
 | 83차시 | 2024.12.01 |  수학 + 구현 | <a href="https://www.acmicpc.net/problem/1033">칵테일</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/259
 | 84차시 | 2024.12.31 |  BFS | <a href="https://www.acmicpc.net/problem/4179">불!</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/261
+| 85차시 | 2025.01.09 |  다익스트라 + 이분 탐색 | <a href="https://www.acmicpc.net/problem/1800">인터넷 설치</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/264
 ---

tgyuuAn/다익스트라/인터넷 설치.py

@@ -0,0 +1,82 @@
+from heapq import *
+from collections import defaultdict
+
+total_node_count, total_edge_count = map(int,input().split(" "))
+
+visited = [False for _ in range(total_node_count+1)]
+distance_table = [int(1e9) for _ in range(total_node_count+1)]
+link_table = defaultdict(lambda: defaultdict(lambda : int(1e9)))
+
+for _ in range(total_edge_count):
+    node1, node2, weight = map(int, input().split(" "))
+    link_table[node1][node2] = weight
+    link_table[node2][node1] = weight
+
+specific_node1, specific_node2 = map(int, input().split(" "))
+distance_table[1] = 0
+heap = [[0,1]]
+
+while heap:
+
+    now_distance, now_node = heappop(heap)
+    visited[now_node] = True
+
+    for link_node in link_table[now_node]:
+
+        if visited[link_node] == True:
+            continue
+
+        if distance_table[link_node] > now_distance + link_table[now_node][link_node]:
+
+            distance_table[link_node] = now_distance + link_table[now_node][link_node]
+            heappush(heap,[distance_table[link_node],link_node])
+
+specific_node1_distance_table = [int(1e9) for _ in range(total_node_count+1)]
+specific_node1_distance_table[specific_node1] = 0
+visited = [False for _ in range(total_node_count+1)]
+heap = [[0,specific_node1]]
+while heap:
+
+    now_distance, now_node = heappop(heap)
+    visited[now_node] = True
+
+    for link_node in link_table[now_node]:
+
+        if visited[link_node] == True:
+            continue
+
+        if specific_node1_distance_table[link_node] > now_distance + link_table[now_node][link_node]:
+
+            specific_node1_distance_table[link_node] = now_distance + link_table[now_node][link_node]
+            heappush(heap,[specific_node1_distance_table[link_node],link_node])
+
+specific_node2_distance_table = [int(1e9) for _ in range(total_node_count+1)]
+specific_node2_distance_table[specific_node2] = 0
+visited = [False for _ in range(total_node_count+1)]
+heap = [[0,specific_node2]]
+while heap:
+
+    now_distance, now_node = heappop(heap)
+    visited[now_node] = True
+
+    for link_node in link_table[now_node]:
+
+        if visited[link_node] == True:
+            continue
+
+        if specific_node2_distance_table[link_node] > now_distance + link_table[now_node][link_node]:
+
+            specific_node2_distance_table[link_node] = now_distance + link_table[now_node][link_node]
+            heappush(heap,[specific_node2_distance_table[link_node],link_node])
+
+first_route = distance_table[specific_node1] + specific_node1_distance_table[specific_node2] + specific_node2_distance_table[total_node_count]
+second_route = distance_table[specific_node2] + specific_node2_distance_table[specific_node1] + specific_node1_distance_table[total_node_count]
+
+if first_route >= int(1e9) and second_route >= int(1e9):
+    print(-1)
+
+elif first_route < second_route:
+    print(first_route)
+
+else:
+    print(second_route)