1197. Minimum Knight Moves

Author: Partho Biswas

README.md

@@ -432,6 +432,7 @@ BFS, DFS, Dijkstra, Floyd–Warshall, Bellman-Ford, Kruskal, Prim's, Minimum Spa
 |21| **[743. Network Delay Time](https://tinyurl.com/yd88jryl)** | [Python](https://tinyurl.com/wu6rdaw/743_Network_Delay_Time.py)|  **[Official](https://tinyurl.com/rmcr2xk)**, **[Dijkstra 1](https://tinyurl.com/r8omw8l)**, **[Dijkstra 2](https://tinyurl.com/sscslz7)**, [Vid 1](https://tinyurl.com/vucexbc), **[Art 1](https://tinyurl.com/vbetlaq)**, [Art 2](https://tinyurl.com/yxdzrw3k), **[Art 3](https://tinyurl.com/whnbv4o)**, **[Art 4](https://tinyurl.com/roq3udj)** | Medium | **TODO: Check again. Very Important. Learned (Dijkstra, Bellman, Floyed).  Check references section** |
 |22| **[261. Graph Valid Tree](https://tinyurl.com/uw9ndt6)** | [Python](https://tinyurl.com/wu6rdaw/261_Graph_Valid_Tree.py)|  [Art 1](https://tinyurl.com/yx6ehrfu), **[Art 2](https://tinyurl.com/tlw6vda)**, **[Art 3](https://tinyurl.com/yhs85tj3)**, [Art 4](https://tinyurl.com/ydkfcc5x) | Medium | Important. BFS, DFS and [Union Find](https://tinyurl.com/yhs85tj3) |
 |23| **[1168. Optimize Water Distribution in a Village](https://tinyurl.com/ygh8sahd)** | [Python](https://tinyurl.com/wu6rdaw/1168_Optimize_Water_Distribution_in_a_Village.py)|  **[Art 1](https://tinyurl.com/yjwwoxv3)**, **[Art 2](https://tinyurl.com/yhc3a7yr)**, **[Art 3](https://tinyurl.com/yf7fjz4v)**, [Art 4](https://tinyurl.com/yh7n9wps) | Hard | TODO: Check AGain. Prim's and Kruskal's algorithm. Important. |
+|24| **[1197. Minimum Knight Moves](https://tinyurl.com/svox8jw)** | [Python](https://tinyurl.com/wu6rdaw/1197_Minimum_Knight_Moves.py)|  **[Art 1](https://tinyurl.com/wed5c6s)** | Medium | TODO: Check AGain. Important. |
 
 
 </p>

leetcode.com/python/1197_Minimum_Knight_Moves.py

@@ -0,0 +1,59 @@
+from collections import deque
+
+# My original code - GOT TLE
+class Solution(object):
+    def minKnightMoves(self, x, y):
+        """
+        :type x: int
+        :type y: int
+        :rtype: int
+        """
+        origin, destination = (0, 0), (abs(x), abs(y))
+        currentLevel = 0
+        if origin == destination:
+            return currentLevel
+        queue = deque([(origin, currentLevel)])
+        visitedSet = set()
+        visitedSet.add(origin)
+        while queue:
+            currentPosition, currentLevel = queue.popleft()
+            currentPossileMoves = self.getPossileMoves(currentPosition[0], currentPosition[1])
+            for move in currentPossileMoves:
+                if move not in visitedSet and move[0] > -4 and move[1] > -4:
+                    if currentPosition == destination:
+                        return currentLevel
+                    visitedSet.add(move)
+                    queue.append((move, currentLevel + 1))
+        return currentLevel
+
+    def getPossileMoves(self, x, y):
+        moves = [(x + 2, y + 1), (x + 2, y - 1), (x - 2, y + 1), (x - 2, y - 1), (x + 1, y + 2), (x - 1, y + 2), (x + 1, y - 2), (x - 1, y - 2)]
+        return moves
+
+
+
+
+
+# Source: https://tinyurl.com/wed5c6s  Same as mine but  - GOT Accepted
+from collections import deque
+class Solution(object):
+    def minKnightMoves(self, x, y):
+        """
+        :type x: int
+        :type y: int
+        :rtype: int
+        """
+        if (x, y)==(0, 0):return 0
+        def bfs(i, j, x, y):
+            open_list = deque([(i,j,0)])
+            seen = {(i, j)}
+            while open_list:
+                i, j, d = open_list.popleft()
+                for di, dj in [(1,2),(2,1),(1,-2),(2,-1),
+                               (-1,2),(-2,1), (-1,-2),(-2,-1)]:
+                    r, c = i+di, j+dj
+                    if (r,c) not in seen and r>-4 and c>-4:
+                        if (r,c)==(x,y):return d+1
+                        seen.add((r,c))
+                        open_list.append((r,c,d+1))
+        return bfs(0,0,abs(x), abs(y))