commit

Siddhipatade · Siddhipatade · commit 25fd4fba163f · 2023-06-28T19:07:29.000+05:30
diff --git a/code/Path with Maximum Probability/A1.py b/code/Path with Maximum Probability/A1.py
@@ -0,0 +1,54 @@
+from typing import List
+
+class Solution:
+    def maxProbability(self, n: int, edges: List[List[int]], succProb: List[float], start: int, end: int) -> float:
+        max_prob = [0] * n
+        max_prob[start] = 1
+
+        for i in range(n - 1):
+            # If there is no larger probability found during an entire round of updates,
+            # stop the update process.
+            has_update = False
+            for j in range(len(edges)):
+                u, v = edges[j]
+                path_prob = succProb[j]
+                if max_prob[u] * path_prob > max_prob[v]:
+                    max_prob[v] = max_prob[u] * path_prob
+                    has_update = True
+                if max_prob[v] * path_prob > max_prob[u]:
+                    max_prob[u] = max_prob[v] * path_prob
+                    has_update = True
+            if not has_update:
+                break
+
+        return max_prob[end]
+
+
+# Take input from the user
+n = int(input("Enter the number of vertices (n): "))
+m = int(input("Enter the number of edges (m): "))
+edges = []
+succProb = []
+
+for i in range(m):
+    print(f"Enter the source and destination vertices of edge {i+1}:")
+    u = int(input())
+    v = int(input())
+    edges.append([u, v])
+
+for i in range(m):
+    print(f"Enter the success probability of edge {i+1}: ")
+    p = float(input())
+    succProb.append(p)
+
+start = int(input("Enter the start vertex: "))
+end = int(input("Enter the end vertex: "))
+
+# Create an instance of Solution
+solution = Solution()
+
+# Calculate maximum probability
+maxProbability = solution.maxProbability(n, edges, succProb, start, end)
+
+# Output the result
+print(f"The maximum probability from vertex {start} to vertex {end} is: {maxProbability}")
diff --git a/code/Path with Maximum Probability/A2.py b/code/Path with Maximum Probability/A2.py
@@ -0,0 +1,56 @@
+from collections import defaultdict, deque
+from typing import List
+
+
+class Solution:
+    def maxProbability(self, n: int, edges: List[List[int]], succProb: List[float], start: int, end: int) -> float:
+        graph = defaultdict(list)
+        for i, (a, b) in enumerate(edges):
+            graph[a].append([b, succProb[i]])
+            graph[b].append([a, succProb[i]])
+
+        max_prob = [0.0] * n
+        max_prob[start] = 1.0
+
+        queue = deque([start])
+        while queue:
+            cur_node = queue.popleft()
+            for nxt_node, path_prob in graph[cur_node]:
+
+                # Only update max_prob[nxt_node] if the current path increases
+                # the probability of reaching nxt_node.
+                if max_prob[cur_node] * path_prob > max_prob[nxt_node]:
+                    max_prob[nxt_node] = max_prob[cur_node] * path_prob
+                    queue.append(nxt_node)
+
+        return max_prob[end]
+
+
+# Take input from the user
+n = int(input("Enter the number of vertices (n): "))
+m = int(input("Enter the number of edges (m): "))
+edges = []
+succProb = []
+
+for i in range(m):
+    print(f"Enter the source and destination vertices of edge {i+1}:")
+    u = int(input())
+    v = int(input())
+    edges.append([u, v])
+
+for i in range(m):
+    print(f"Enter the success probability of edge {i+1}: ")
+    p = float(input())
+    succProb.append(p)
+
+start = int(input("Enter the start vertex: "))
+end = int(input("Enter the end vertex: "))
+
+# Create an instance of Solution
+solution = Solution()
+
+# Calculate maximum probability
+maxProbability = solution.maxProbability(n, edges, succProb, start, end)
+
+# Output the result
+print(f"The maximum probability from vertex {start} to vertex {end} is: {maxProbability}")
