Merge pull request #244 from AlgoLeadMe/28-H0ngJu

28-H0ngJu

H0ngJu/README.md

@@ -29,5 +29,5 @@
 | 25차시 | 2024.08.17 | DFS | [친구비](https://www.acmicpc.net/problem/16562) | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/234 |
 | 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 |
 ---

H0ngJu/벨만포드/타임머신.py

@@ -0,0 +1,36 @@
+import sys
+
+INF = 1e8
+
+def input() : return sys.stdin.readline().rstrip()
+
+N, M = map(int, input().split())
+bus = [[] for _ in range(N+1)]
+distance = [INF] * (N+1)
+
+for i in range(M):
+    A, B, C = map(int, input().split())
+    bus[A].append([B, C])
+
+def BellmanFord(start):
+    distance[start] = 0
+
+    for i in range(N):
+        for j in range(1, N+1):
+            for n, w in bus[j]:
+                if distance[j] != INF and distance[n] > distance[j] + w:
+                    distance[n] = distance[j] + w
+                    if i == N-1:
+                        return True
+    return False
+
+check_negative = BellmanFord(1)
+
+if check_negative:
+    print("-1")
+else:
+    for i in range(2, N+1):
+        if distance[i] == INF:
+            print("-1")
+        else:
+            print(distance[i])