2024-11-08

H0ngJu/README.md

@@ -30,6 +30,8 @@
 | 26차시 | 2024.08.24 |  그리디  |                   [신입사원](https://www.acmicpc.net/problem/1946)                    | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/237 |
 | 27차시 | 2024.08.27 |   DFS    |                  [트리의 지름](https://www.acmicpc.net/problem/1967)                  | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/240 |
 | 28차시 | 2024.09.04 | 벨만포드 |                   [타임머신](https://www.acmicpc.net/problem/11657)                   | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/244 |
-| 29차시 | 2024.09.06 |   구현   |[톱니바퀴](https://www.acmicpc.net/problem/14891)                   | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/245 |
+| 29차시 | 2024.09.06 |   구현   |                   [톱니바퀴](https://www.acmicpc.net/problem/14891)                   | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/245 |
 | 30차시 | 2024.09.27 |   수학   |         [Fly me to the Alpha Centauri](https://www.acmicpc.net/problem/1011)          | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/248 |
-| 31차시 | 2024.10.05 | 정렬 | [선 긋기](https://www.acmicpc.net/problem/2170) | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/249 |
+| 31차시 | 2024.10.05 |   정렬   |                    [선 긋기](https://www.acmicpc.net/problem/2170)                    | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/249 |
+
+| 33차시 | 2024.11.08 | 백트래킹 | [병원 거리 최소화](https://www.codetree.ai/training-field/frequent-problems/problems/min-of-hospital-distance/submissions?page=11&pageSize=5) | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/253 |

H0ngJu/백트래킹/병원 거리 최소화.py

@@ -0,0 +1,112 @@
+import sys
+
+def input() : return sys.stdin.readline().rstrip()
+
+n, m = map(int, input().split())
+hospital = []
+person = []
+info = [[] for _ in range(n)]
+
+# 사람, 병원 정보 받기
+for i in range(n):
+    info[i].extend(list(map(int, input().split())))
+    for j in range(n):
+        if info[i][j] == 2:
+            hospital.append((i,j))
+        if info[i][j] == 1:
+            person.append((i,j))
+
+distance = [[0 for _ in range(len(hospital))] for _ in range(len(person))]
+
+for i in range(len(person)):
+    px, py = person[i]
+    for j in range(len(hospital)):
+        hx, hy = hospital[j]
+        distance[i][j] = abs(px-hx) + abs(py-hy)
+
+# hospital 위치 중에 m개를 선택해서 최솟값 구하기
+hospital_arr = [i for i in range(len(hospital))]
+all_combinations = []
+
+def combination(start, depth, combination_arr):
+    if depth == m: # m만큼 찾으면 return
+        all_combinations.append(combination_arr[:])
+        return
+    for i in range(start, len(hospital_arr)):
+        combination_arr.append(hospital_arr[i]) # 원소 일단 넣고
+        combination(i + 1, depth + 1, combination_arr) # 재귀 돌림
+        combination_arr.pop() # 다시 뽑은거 복귀 -> [1,2,3]을 구하면, 3빼고 다시 다음 반복문 넣어서 [1,2,4] 가능
+
+combination(0, 0, [])
+
+min_distance_sum = 1e9
+for hospitals_combination in all_combinations:
+    cur_distance = 0
+
+    for i in range(len(person)):
+        dist = 1e9
+        for j in hospitals_combination:
+            dist = min(dist, distance[i][j])
+        cur_distance += dist
+
+    min_distance_sum = min(min_distance_sum, cur_distance)
+
+print(min_distance_sum)
+
+# --- combination -----
+
+# import sys
+# import itertools
+
+# def input() : return sys.stdin.readline().rstrip()
+
+# n, m = map(int, input().split())
+# hospital = []
+# person = []
+# info = [[] for _ in range(n)]
+
+# # 사람, 병원 정보 받기
+# for i in range(n):
+#     info[i].extend(list(map(int, input().split())))
+#     for j in range(n):
+#         if info[i][j] == 2:
+#             hospital.append((i,j))
+#         if info[i][j] == 1:
+#             person.append((i,j))
+
+# distance = [[0 for _ in range(len(hospital))] for _ in range(len(person))]
+
+# for i in range(len(person)):
+#     px, py = person[i]
+#     for j in range(len(hospital)):
+#         hx, hy = hospital[j]
+#         distance[i][j] = abs(px-hx) + abs(py-hy)
+
+# # hospital 위치 중에 m개를 선택해서 최솟값 구하기
+
+# min_distance_sum = 1e9
+# combbination_arr = [i for i in range(len(hospital))]
+
+# for hospitals_combination in itertools.combinations(combbination_arr, m):
+#     cur_distance = 0
+
+#     for i in range(len(person)):
+#         dist = 1e9
+#         for j in hospitals_combination:
+#             dist = min(dist, distance[i][j])
+#         cur_distance += dist
+
+#     min_distance_sum = min(min_distance_sum, cur_distance)
+
+# print(min_distance_sum)
+
+# # 빈자리면 0, 사람이면 1, 병원이면 2
+# # 출력은 최소 거리
+
+# # 병원의 수 만큼 배열을 생성해서, 각 사람마다의 최소 거리를 계산한다.
+# # 각 병원의 거리 총 합을 계산해서 정렬한다. -> 문제 : 사람마다 다른 병원이 최소 거리일 수 있지만, 해당 가능성을 무시하게 됨
+
+# # 각 사람마다 각 병원의 거리를 계산한다.
+# # [[1,2,4,5], [1,2,4,5]]의 형태
+# # 병원 중 m개를 고르는 조합
+# # 조합에서 최소거리 갱신하여 찾기