43-pknujsp

pknujsp/BFS/42-다리 만들기.py

@@ -0,0 +1,73 @@
+from collections import *
+
+map_size = int(input())
+matrix = [list(map(int, input().split())) for _ in range(map_size)]
+
+directions = [(1, 0), (0, -1), (-1, 0), (0, 1)]
+island_id = 2
+costs = [[0] * map_size for _ in range(map_size)]
+
+# 다리를 놓을 위치를 저장할 큐
+bridge_queue = deque()
+
+# 전체 맵을 순회하면서 각 섬에 ID 부여
+for row in range(map_size):
+    for col in range(map_size):
+
+        if matrix[row][col] != 1:
+            continue
+
+        # 현재 칸을 시작으로 하는 섬에 고유 ID 할당
+        matrix[row][col] = island_id
+        queue = deque([(row, col)])
+
+        # BFS를 통해 같은 섬인 육지에 ID 할당
+        while queue:
+            r, c = queue.popleft()
+            for dr, dc in directions:
+                nr, nc = r + dr, c + dc
+
+                if not 0 <= nr < map_size or not 0 <= nc < map_size:
+                    continue
+
+                # 다른 섬과 연결된 바다 영역에 접근하면 종료
+                if 1 < matrix[nr][nc] < island_id:
+                    print(1)
+                    exit()
+
+                # 새로운 육지 발견 시 큐에 추가
+                if matrix[nr][nc] == 1:
+                    queue.append((nr, nc))
+                # 육지와 바로 맞닿은 바다 영역을 다리 후보로 추가
+                elif matrix[nr][nc] == costs[nr][nc] == 0:
+                    bridge_queue.append((nr, nc, 1, island_id))
+
+                costs[nr][nc] = 1
+                matrix[nr][nc] = island_id
+
+        island_id += 1
+
+min_cost = int(1e6)
+
+# 다리 후보 위치를 순회하며 최소 다리 길이 계산
+while bridge_queue:
+    r, c, cost, curr_island_id = bridge_queue.popleft()
+
+    for dr, dc in directions:
+        nr, nc = r + dr, c + dc
+
+        if not 0 <= nr < map_size or not 0 <= nc < map_size:
+            continue
+
+        # 아직 다리가 놓이지 않은 바다 영역이면
+        # 다리 길이를 증가시키고 큐에 추가
+        if costs[nr][nc] == 0:
+            bridge_queue.append((nr, nc, cost + 1, curr_island_id))
+
+            costs[nr][nc] = cost + 1
+            matrix[nr][nc] = curr_island_id
+        # 다른 섬과 연결된 다리 영역에 접근하였다면 최소 비용을 갱신
+        elif matrix[nr][nc] > 1 and matrix[nr][nc] != curr_island_id:
+            min_cost = min(min_cost, cost + costs[nr][nc])
+
+print(min_cost)

pknujsp/BRUTE_FORCE/38-자물쇠와 열쇠.py

@@ -0,0 +1,50 @@
+# 자물쇠의 중간 부분이 모두 1인지 확인
+def is_valid(new_lock):
+    length = len(new_lock) // 3
+
+    for r in range(length, length * 2):
+        for c in range(length, length * 2):
+            if new_lock[r][c] != 1:
+                return False
+
+    return True
+
+def solution(key, lock):
+    n = len(lock)
+    k = len(key)
+    new_lock = [[0] * (n * 3) for _ in range(n * 3)]
+
+    for r in range(n):
+        for c in range(n):
+            new_lock[r + n][c + n] = lock[r][c]
+
+    for _ in range(4):
+        rev_key = key[::-1]
+        key = []
+        for c in range(k):
+            row = []
+            for r in range(k):
+                row.append(rev_key[r][c])
+            key.append(row)
+
+        """
+        열쇠를 돌리는 로직은 한 줄로도 구현가능 합니다
+        key = [row for row in zip(*reversed(key))]
+        """
+
+        for r in range(n * 2):
+            for c in range(n * 2):
+                # 자물쇠에 열쇠를 끼운다
+                for i in range(k):
+                    for j in range(k):
+                        new_lock[r + i][c + j] += key[i][j]
+
+                # 자물쇠에 열쇠가 딱 들어갔는지 확인
+                if is_valid(new_lock):
+                    return True
+
+                # 자물쇠에서 열쇠를 빼서 복구시킨다
+                for i in range(k):
+                    for j in range(k):
+                        new_lock[r + i][c + j] -= key[i][j]
+    return False

pknujsp/README.md

@@ -38,4 +38,10 @@
 | 34차시 | 2024.02.12 |       BFS       |                        [이분 그래프](https://www.acmicpc.net/problem/1707)                        | [#135](https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/135) |
 | 35차시 | 2024.02.18 |     그리디      |                         [선물할인](https://www.acmicpc.net/problem/25947)                         | [#137](https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/137) |
 | 36차시 | 2024.02.21 |    이진탐색     |                       [휴게소 세우기](https://www.acmicpc.net/problem/1477)                       | [#143](https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/143) |
-| 37차시 | 2024.03.04 |      구현       |         [n+1 카드게임](https://school.programmers.co.kr/learn/courses/30/lessons/258707)          | [#149](https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/149) |
+| 37차시 | 2024.03.04 |      구현       |         [n+1 카드게임](https://school.programmers.co.kr/learn/courses/30/lessons/258707)          | [#149](https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/149) |
+| 38차시 | 2024.03.08 |   BRUTE_FORCE   |         [자물쇠와 열쇠](https://school.programmers.co.kr/learn/courses/30/lessons/60059)          | [#154](https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/154) |
+| 39차시 | 2024.03.19 |       큐        |        [디스크 컨트롤러](https://school.programmers.co.kr/learn/courses/30/lessons/42627)         | [#163](https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/163) |
+| 40차시 | 2024.03.22 |     그리디      |                           [센서](https://www.acmicpc.net/problem/2212)                            | [#168](https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/168) |
+| 41차시 | 2024.03.25 |   다익스트라    |                         [알고스팟](https://www.acmicpc.net/problem/1261)                          | [#169](https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/169) |
+| 42차시 | 2024.03.29 |       BFS       |                        [다리 만들기](https://www.acmicpc.net/problem/2146)                        | [#173](https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/173) |
+| 43차시 | 2024.04.03 |     그리디      |                           [저울](https://www.acmicpc.net/problem/2437)                            | [#175](https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/175) |

pknujsp/그리디/40-센서.py

@@ -0,0 +1,18 @@
+from sys import *
+
+N = int(stdin.readline())
+K = int(stdin.readline())
+SENSORS = sorted(set(map(int, stdin.readline().split())))
+
+if K >= N:
+    print(0)
+    exit()
+
+distances = [SENSORS[i] - SENSORS[i - 1] for i in range(1, len(SENSORS))]
+distances.sort(reverse=True)
+
+result = 0
+for i in range(K - 1, len(distances)):
+    result += distances[i]
+
+print(result)

pknujsp/그리디/43-저울.py

@@ -0,0 +1,13 @@
+N = int(input())
+weights = list(map(int, input().split()))
+weights.sort()
+
+x = 0
+for weight in weights:
+    # x + 1이 현재 추의 무게보다 작다면, 측정이 불가능함
+    if x + 1 < weight:
+        break
+
+    x += weight
+
+print(x + 1)

pknujsp/다익스트라/41-알고스팟.py

@@ -0,0 +1,33 @@
+from heapq import *
+from sys import *
+
+C, R = map(int, stdin.readline().split())
+arr = [list(map(int, list(stdin.readline().strip()))) for _ in range(R)]
+
+drc = ((1,0),(-1,0),(0,1),(0,-1))
+visited = [[False] * C for _ in range(R)]
+heap = [(0, 0, 0)]
+target_r = R - 1
+target_c = C - 1
+
+while heap:
+    cost, r, c = heappop(heap)
+
+    if r == target_r and c == target_c:
+        print(cost)
+        break
+    if visited[r][c]:
+        continue      
+
+    visited[r][c] = True
+
+    for dr, dc in drc:
+        nr = r + dr
+        nc = c + dc
+
+        if not 0 <= nr < R or not 0 <= nc < C:
+            continue
+        if visited[nr][nc]:
+            continue
+
+        heappush(heap, (cost + arr[nr][nc], nr, nc))

pknujsp/큐/39-디스크 컨트롤러.py

@@ -0,0 +1,24 @@
+from heapq import *
+from collections import *
+
+def solution(jobs):
+    jobs = deque(sorted(jobs))
+    jobs_num = len(jobs) 
+
+    curr_time = wait_time = 0
+    heap = []
+
+    while heap or jobs:
+        while jobs and jobs[0][0] <= curr_time:
+            requested_time, duration = jobs.popleft()
+            heappush(heap, (duration, requested_time))
+
+        if heap:
+            duration, requested_time = heappop(heap)
+
+            curr_time += duration
+            wait_time += curr_time - requested_time
+        else:
+            curr_time += 1
+
+    return wait_time // jobs_num