Esther Annorzie - C17 - Section A

graphs/minimum_effort_path.py

@@ -1,3 +1,5 @@
+import heapq
+
 def min_effort_path(heights):
     """ Given a 2D array of heights, write a function to return
         the path with minimum effort.
@@ -15,4 +17,31 @@ def min_effort_path(heights):
         int
             minimum effort required to navigate the path from (0, 0) to heights[rows - 1][columns - 1]
     """
-    pass
+    if not heights:
+        return 0
+
+    rows = len(heights)
+    cols = len(heights[0])
+    visited = set()
+
+    min_eff = 0
+    start = [(0, 0, 0)]
+    dirs = [(-1, 0), (0, 1), (0, -1), (1, 0)]
+
+    while start:
+        eff, row, col = heapq.heappop(start)
+        visited.add((row, col))
+        min_eff = max(min_eff, eff)
+
+        if row == rows - 1 and col == cols - 1: 
+            return min_eff
+
+        for x_coor, y_coor in dirs:
+            next_row = row + x_coor
+            next_col = col + y_coor
+
+            if rows > next_row >= 0 <= next_col < cols:
+                if (next_row, next_col) not in visited:
+                    heapq.heappush(start, (abs(heights[row][col] - heights[next_row][next_col]), next_row, next_col))
+
+    return min_eff

requirements.txt

@@ -4,5 +4,5 @@ packaging==20.8
 pluggy==0.13.1
 py==1.10.0
 pyparsing==2.4.7
-pytest==6.2.1
+pytest==6.2.5
 toml==0.10.2