solve(programmers): LV3_합승 택시 요금_py

# id: 문제 id를 숫자로 작성
# categories : 해당 문제의 유형을 ,로 구분하여 작성
# tags : 해당 문제의 태그를 ,로 구분하여 작성
# time : 해당 문제 풀이에 걸린 시간을 분단위 숫자로 작성
# try : 해당 문제에 몇번의 시도를 했는지 숫자로 작성
# help: 해당 문제에 외부의 도움을 받았는지 true/false로 작성
# url : 해당 문제의 url을 작성
id: 72413
categories: [탐색, 다익스트라, 플로이드]
tags: [2021 KAKAO BLIND RECRUITMENT
]
time: 120
try: 5
help: true
url: https://school.programmers.co.kr/learn/courses/30/lessons/72413#

src/programmers/level_1/그래프/LV3_합승_택시_요금.py

@@ -0,0 +1,68 @@
+import heapq
+import sys
+
+def dijkstra(n,graph,start):
+    pq=[(0,start)]
+    heapq.heapify(pq)
+    min_l=[sys.maxsize for _ in range(n+1)]
+    min_l[start]=0
+    visited=[False for _ in range(n+1)]
+
+    while pq:
+        (_,current)=heapq.heappop(pq)
+        if visited[current]:
+            continue
+        visited[current]=True
+        for nx,nc in graph[current]:
+            if visited[nx]:
+                continue
+            min_l[nx]=min(min_l[nx],min_l[current]+nc)
+            heapq.heappush(pq,(min_l[nx],nx))
+        #print(pq)
+    return min_l
+
+def solution_with_dijkstra(n, s, a, b, fares):
+
+    graph={}
+    for st,fin,c in fares:
+        if st not in graph:
+            graph[st]=[]
+        if fin not in graph:
+            graph[fin]=[]
+        graph[st].append((fin,c))
+        graph[fin].append((st,c))
+
+    start_to=dijkstra(n,graph,s)
+    a_to=dijkstra(n,graph,a)
+    b_to=dijkstra(n,graph,b)
+
+
+    ans=sys.maxsize
+    for i in range(1,n+1):
+        total=start_to[i]+a_to[i]+b_to[i]
+        ans=min(ans,total)
+
+    return ans
+
+def solution_with_floyd(n, s, a, b, fares):
+    import sys
+    min_l=[[sys.maxsize if i!=j else 0 for j in range(n+1)] for i in range(n+1)]
+    for st,fin,c in fares:
+        min_l[st][fin]=c
+        min_l[fin][st]=c
+
+    for via in range(1,n+1):
+        for start in range(1,n+1):
+            for finish in range(1,n+1):
+                if start==via or finish==via or start==finish:
+                    continue
+                min_l[start][finish]=min(min_l[start][finish],min_l[start][via]+min_l[via][finish])
+                min_l[finish][start]=min_l[start][finish]
+    ans=min_l[s][a]+min_l[s][b]
+    for i in range(1,n+1):
+        together=min_l[s][i]
+        to_a=min_l[i][a]
+        to_b=min_l[i][b]
+        total=together+to_a+to_b
+        ans=min(ans,total)
+    return ans