119차 1번 문제풀이

Author: hangyeol

live11/test119/문제1/백한결.py

@@ -0,0 +1,42 @@
+import heapq
+import sys
+from collections import defaultdict
+
+
+def main():
+    input = sys.stdin.readline
+
+    N, M = map(int, input().split())
+
+    problems = defaultdict(list)
+    aheadResolveProblems = [0] * (N+1)
+
+    for i in range(M):
+        A, B = map(int, input().split())
+        problems[A].append(B)
+        aheadResolveProblems[B] += 1
+
+    result = []
+    heap = []
+
+    for i in range(1, N+1):
+        if aheadResolveProblems[i] == 0:
+            heapq.heappush(heap, i)
+
+    while heap:
+        now = heapq.heappop(heap)
+        result.append(now)
+
+        for next in problems[now]:
+            aheadResolveProblems[next] -= 1
+            if aheadResolveProblems[next] == 0:
+                heapq.heappush(heap, next)
+
+    print(*result)
+
+if __name__ == '__main__':
+    main()
+
+# 1234
+# 1. 4는 2보다 먼저 푸는 것이 좋음 -> 1 4 2 3
+# 2. 3은 1보다 먼저 푸는 것이 좋음 -> 3 1 4 2