Merge pull request #204 from wellFoundedDevelopers/jimin/50week

[이지민] - 북쪽나라의 도로, 숫자고르기, 연구소2

src/main/kotlin/jimin/50week/북쪽나라의 도로.py

@@ -0,0 +1,40 @@
+'''
+
+https://dodobow.tistory.com/35
+
+근데 왜 1과 1로 돌고 난 후의 max만 확인하면 될까?
+'''
+
+import sys
+from collections import deque
+
+roads = [[] for _ in range(10_001)]
+while True:
+    try:
+        a, b, c = map(int, sys.stdin.readline().split())
+        roads[a].append([b, c])
+        roads[b].append([a, c])
+    except:
+        break
+
+
+def bfs(start):
+    queue = deque([start])
+
+    visited[start] = 0
+
+    while queue:
+        now = queue.popleft()
+
+        for i, w in roads[now]:
+           if visited[i] == -1:
+               visited[i] = visited[now] + w
+               queue.append(i)
+
+
+visited = [-1 for _ in range(10_001)]
+bfs(1)
+s = visited.index(max(visited))
+visited = [-1 for _ in range(10_001)]
+bfs(s)
+print(max(visited))

src/main/kotlin/jimin/50week/숫자고르기.py

@@ -0,0 +1,36 @@
+'''
+처음에는 그냥 dfs로 했더니 시간초과났다
+
+사이클을 도는 친구를 찾아야한다..
+https://velog.io/@deannn/BOJ-%EB%B0%B1%EC%A4%80-2668%EB%B2%88-%EC%88%AB%EC%9E%90%EA%B3%A0%EB%A5%B4%EA%B8%B0-Python
+참고
+'''
+
+import sys
+n = int(sys.stdin.readline())
+numbers = [0]
+for i in range(n):
+    numbers.append(int(sys.stdin.readline()))
+
+answer = set()
+
+
+def dfs(first, second, now):
+    first.add(now)
+    second.add(numbers[now])
+    if numbers[now] in first:
+        if first == second:
+            answer.update(first)
+            return
+        return
+    return dfs(first, second, numbers[now])
+
+
+for i in range(1, n + 1):
+    if i not in answer:
+        dfs(set(), set(), i)
+
+print(len(answer))
+for num in sorted(list(answer)):
+    print(num)
+

src/main/kotlin/jimin/50week/연구소2.py

@@ -0,0 +1,70 @@
+import sys
+from collections import deque
+from itertools import combinations
+
+n, m = map(int, sys.stdin.readline().split())
+
+ground = []
+for i in range(n):
+    ground.append(list(map(int, sys.stdin.readline().split())))
+
+mini = 100_000_000
+
+
+def bfs(viruses):
+    global n, mini, ground
+    queue = deque(viruses)
+
+    visited = [[0 for _ in range(n)] for _ in range(n)]
+    for i in range(n):
+        for j in range(n):
+            if ground[i][j] == 1:
+                visited[i][j] = -1
+
+    for x, y in viruses:
+        visited[x][y] = 1
+
+    dx = [0, 0, -1, 1]
+    dy = [1, -1, 0, 0]
+
+    while queue:
+        nx, ny = queue.popleft()
+
+        for i in range(4):
+            if 0 <= nx + dx[i] < n and 0 <= ny + dy[i] < n and visited[nx + dx[i]][ny + dy[i]] == 0:
+                queue.append([nx + dx[i], ny + dy[i]])
+                visited[nx + dx[i]][ny + dy[i]] = visited[nx][ny] + 1
+
+    can = True
+    for i in range(n):
+        for j in range(n):
+            if visited[i][j] == 0:
+                can = False
+                break
+
+    if not can:
+        return
+
+    maxi = 0
+    for v in visited:
+        maxi = max(maxi, max(v))
+
+    mini = min(maxi - 1, mini)
+
+
+possible = []
+for i in range(n):
+    for j in range(n):
+        if ground[i][j] == 2:
+            possible.append([i, j])
+
+
+for combi in combinations(possible, m):
+    bfs(list(combi))
+
+if mini == 100_000_000:
+    print(-1)
+else:
+    print(mini)
+
+