From b53f274a0a309aac5f719ce1a7556147bcd08243 Mon Sep 17 00:00:00 2001
From: Bhanuka Rathnayaka <bhanuka2017@gmail.com>
Date: Tue, 22 Oct 2019 11:51:48 +0530
Subject: [PATCH] Solution for Hackerrank Dijkstra Shortest Reach 2

---
 .../Graph Theory/DijkstraShortestReach2.py    | 49 +++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 Algorithms/Graph Theory/DijkstraShortestReach2.py

diff --git a/Algorithms/Graph Theory/DijkstraShortestReach2.py b/Algorithms/Graph Theory/DijkstraShortestReach2.py
new file mode 100644
index 0000000..8a16a1c
--- /dev/null
+++ b/Algorithms/Graph Theory/DijkstraShortestReach2.py	
@@ -0,0 +1,49 @@
+
+from collections import defaultdict
+
+import heapq
+
+
+def dijkstra(S, N, G):
+    D    = {}
+    H    = [(0, S)]
+
+    for n in range(1, N + 1):
+        D[n] = float('inf')
+
+    D[S] = 0
+
+    while H:
+        t = heapq.heappop(H)
+        for h in G[t[1]]:
+            if D[h[0]] > D[t[1]] + h[1]:
+                D[h[0]] = D[t[1]] + h[1]
+                if (h[1], h[0]) in H:
+                    H.remove((h[1], h[0]))
+                    heapq.heapify(H)
+                heapq.heappush(H, (D[h[0]], h[0]))
+
+    return D
+
+
+def main():
+    T = int(input())
+
+    for _ in range(T):
+        N, M = [int(i) for i in input().split()]
+
+        G    = defaultdict(set)
+
+        for _ in range(M):
+            e = [int(i) for i in input().split()]
+            G[e[0]].add((e[1], e[2]))
+            G[e[1]].add((e[0], e[2]))
+
+        S    = int(input())
+
+        D    = dijkstra(S, N, G)
+        print(' '.join(str(D[n]) if D[n] != float('inf') else '-1' for n in range(1, N + 1) if n != S))
+
+
+if __name__ == "__main__":
+    main()