D. J.:

- Added the leetcode problem and solution for 724, 1732 and 1991

Author: nobodyPerfecZ

README.md

@@ -106,7 +106,7 @@
 - [61 Rotate List](https://leetcode.com/problems/rotate-list/description/)
 - [63 Unique Paths II](https://leetcode.com/problems/unique-paths-ii/description/)
 - [64 Minimum Path Sum](https://leetcode.com/problems/minimum-path-sum/description/)
-- [66 Plus One](https://leetcode.com/problems/plus-one/description)
+- [66 Plus One](https://leetcode.com/problems/plus-one/description/)
 - [67 Add Binary](https://leetcode.com/problems/add-binary/description/)
 - [68 Text Justification](https://leetcode.com/problems/text-justification/description/)
 - [69 Sqrt(x)](https://leetcode.com/problems/sqrtx/description/)
@@ -229,6 +229,7 @@
 - [673 Number of Longest Increasing Subsequence](https://leetcode.com/problems/number-of-longest-increasing-subsequence/description/)
 - [712 Minimum ASCII Delete Sum for Two Strings](https://leetcode.com/problems/minimum-ascii-delete-sum-for-two-strings/description/)
 - [714 Best Time to Buy and Sell Stock with Transaction Fee](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-transaction-fee/description/)
+- [724 Find Pivot Index](https://leetcode.com/problems/find-pivot-index/description/)
 - [740 Delete and Earn](https://leetcode.com/problems/delete-and-earn/description/)
 - [746 Min Cost Climbing Stairs](https://leetcode.com/problems/min-cost-climbing-stairs/description/)
 - [790 Domino and Tromino Tiling](https://leetcode.com/problems/domino-and-tromino-tiling/description/)
@@ -242,7 +243,9 @@
 - [1143 Longest Common Subsequence](https://leetcode.com/problems/longest-common-subsequence/description/)
 - [1218 Longest Arithmetic Subsequence of Given Difference](https://leetcode.com/problems/longest-arithmetic-subsequence-of-given-difference/description/)
 - [1312 Minimum Insertion Steps to Make a String Palindrome](https://leetcode.com/problems/minimum-insertion-steps-to-make-a-string-palindrome/description/)
-- [1534 Count Good Triplets](https://leetcode.com/problems/count-good-triplets/description)
+- [1534 Count Good Triplets](https://leetcode.com/problems/count-good-triplets/description/)
+- [1732 Find the Highest Altitude](https://leetcode.com/problems/find-the-highest-altitude/description/)
+- [1991 Find the Middle Index in Array](https://leetcode.com/problems/find-the-middle-index-in-array/description/)
 - [1922 Count Good Numbers](https://leetcode.com/problems/count-good-numbers/description/)
 - [1964 Find the Longest Valid Obstacle Course at Each Position](https://leetcode.com/problems/find-the-longest-valid-obstacle-course-at-each-position/description/)
 - [2140 Solving Questions With Brainpower](https://leetcode.com/problems/solving-questions-with-brainpower/description/)

awesome_python_leetcode/_1732_find_the_highest_altitude.py

@@ -0,0 +1,24 @@
+from typing import List
+
+
+class Solution:
+    """Base class for all LeetCode Problems."""
+
+    def largestAltitude(self, gain: List[int]) -> int:
+        """
+        There is a biker going on a road trip. The road trip consists of n + 1 points
+        at different altitudes. The biker starts his trip on point 0 with altitude
+        equal 0.
+
+        You are given an integer array gain of length n where gain[i] is the net gain
+        in altitude between points i and i + 1 for all (0 <= i < n). Return the highest
+        altitude of a point.
+        """
+        # Time complexity: O(n)
+        # Space complexity: O(1)
+        res = 0
+        altitude = 0
+        for g in gain:
+            altitude += g
+            res = max(res, altitude)
+        return res

awesome_python_leetcode/_1991_find_the_middle_index_in_array.py

@@ -0,0 +1,31 @@
+from typing import List
+
+
+class Solution:
+    """Base class for all LeetCode Problems."""
+
+    def findMiddleIndex(self, nums: List[int]) -> int:
+        """
+        Given a 0-indexed integer array nums, find the leftmost middleIndex (i.e., the
+        smallest amongst all the possible ones).
+
+        A middleIndex is an index where nums[0] + nums[1] + ... +
+        nums[middleIndex-1] == nums[middleIndex+1] + nums[middleIndex+2] + ... +
+        nums[nums.length-1].
+
+        If middleIndex == 0, the left side sum is considered to be 0. Similarly, if
+        middleIndex == nums.length - 1, the right side sum is considered to be 0.
+
+        Return the leftmost middleIndex that satisfies the condition, or -1 if there is
+        no such index.
+        """
+        # Time complexity: O(n)
+        # Space complexity: O(1)
+        left = 0
+        right = sum(nums)
+        for i in range(len(nums)):
+            right -= nums[i]
+            if left == right:
+                return i
+            left += nums[i]
+        return -1

awesome_python_leetcode/_724_find_pivot_index.py

@@ -0,0 +1,30 @@
+from typing import List
+
+
+class Solution:
+    """Base class for all LeetCode Problems."""
+
+    def pivotIndex(self, nums: List[int]) -> int:
+        """
+        Given an array of integers nums, calculate the pivot index of this array.
+
+        The pivot index is the index where the sum of all the numbers strictly to the
+        left of the index is equal to the sum of all the numbers strictly to the
+        index's right.
+
+        If the index is on the left edge of the array, then the left sum is 0 because
+        there are no elements to the left. This also applies to the right edge of the
+        array.
+
+        Return the leftmost pivot index. If no such index exists, return -1.
+        """
+        # Time complexity: O(n)
+        # Space complexity: O(1)
+        left = 0
+        right = sum(nums)
+        for i in range(len(nums)):
+            right -= nums[i]
+            if left == right:
+                return i
+            left += nums[i]
+        return -1

tests/test_1732_find_the_highest_altitude.py

@@ -0,0 +1,18 @@
+from typing import List
+
+import pytest
+
+from awesome_python_leetcode._1732_find_the_highest_altitude import Solution
+
+
+@pytest.mark.parametrize(
+    argnames=["gain", "expected"],
+    argvalues=[
+        ([-5, 1, 5, 0, -7], 1),
+        ([-4, -3, -2, -1, 4, 3, 2], 0),
+    ],
+)
+def test_func(gain: List[int], expected: int):
+    """Tests the solution of a LeetCode problem."""
+    largest_altitude = Solution().largestAltitude(gain)
+    assert largest_altitude == expected

tests/test_1991_find_the_middle_index_in_array.py

@@ -0,0 +1,19 @@
+from typing import List
+
+import pytest
+
+from awesome_python_leetcode._1991_find_the_middle_index_in_array import Solution
+
+
+@pytest.mark.parametrize(
+    argnames=["nums", "expected"],
+    argvalues=[
+        ([2, 3, -1, 8, 4], 3),
+        ([1, -1, 4], 2),
+        ([2, 5], -1),
+    ],
+)
+def test_func(nums: List[int], expected: int):
+    """Tests the solution of a LeetCode problem."""
+    middle_idx = Solution().findMiddleIndex(nums)
+    assert middle_idx == expected

tests/test_724_find_pivot_index.py

@@ -0,0 +1,19 @@
+from typing import List
+
+import pytest
+
+from awesome_python_leetcode._724_find_pivot_index import Solution
+
+
+@pytest.mark.parametrize(
+    argnames=["nums", "expected"],
+    argvalues=[
+        ([1, 7, 3, 6, 5, 6], 3),
+        ([1, 2, 3], -1),
+        ([2, 1, -1], 0),
+    ],
+)
+def test_func(nums: List[int], expected: int):
+    """Tests the solution of a LeetCode problem."""
+    pivot_idx = Solution().pivotIndex(nums)
+    assert pivot_idx == expected