Create MinCostClimbingStairs.py

LeetCode/MinCostClimbingStairs.py

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+"""
+On a staircase, the i-th step has some non-negative cost cost[i] assigned (0 indexed).
+Once you pay the cost, you can either climb one or two steps. You need to find minimum cost to reach the top of the floor, and you can 
+either start from the step with index 0, or the step with index 1.
+Example 1:
+Input: cost = [10, 15, 20]
+Output: 15
+Explanation: Cheapest is start on cost[1], pay that cost and go to the top.
+Example 2:
+Input: cost = [1, 100, 1, 1, 1, 100, 1, 1, 100, 1]
+Output: 6
+Explanation: Cheapest is start on cost[0], and only step on 1s, skipping cost[3].
+Note:
+cost will have a length in the range [2, 1000].
+Every cost[i] will be an integer in the range [0, 999].
+"""
+
+#only 256/276 test cases passed
+class Solution:
+    def minCostClimbingStairs(self, cost: List[int]) -> int:
+        def pickStep(i):
+            size = len(cost)
+            [pathThree,pathFour] = [cost[i+2]]*2
+            [pathOne,pathTwo] = [cost[i+1]]*2
+            if i+3 < size:
+                pathOne += cost[i+3]
+                pathTwo += cost[i+3]
+                pathThree += cost[i+3]
+            if i+4 < size:
+                pathTwo += cost[i+4]
+                pathFour += cost[i+4]
+            stepOne = min(pathOne,pathTwo)
+            stepTwo = min(pathFour,pathThree)
+            if stepOne < stepTwo:
+                return i+1
+            else:
+                return i+2
+
+        index = -1
+        cheapest = 0
+        while index < len(cost)-2:
+            index = pickStep(index)
+            cheapest += cost[index]
+        return cheapest
+
+"""
+My Solution
+
+"""
+
+"""
+Fastest Solution
+
+"""