solved stk + intervals questions

Author: Ataba29

Easy/228.py

@@ -0,0 +1,17 @@
+from typing import List
+
+
+class Solution:
+    def summaryRanges(self, nums: List[int]) -> List[str]:
+        if not nums:  # check for empty list
+            return []
+        res = []
+        l = 0
+        for r in range(1, len(nums)):
+            if nums[r] != nums[r - 1] + 1:
+                res.append(
+                    f"{nums[l]}->{nums[r - 1]}" if l != r - 1 else f"{nums[r - 1]}"
+                )
+                l = r
+        res.append(f"{nums[l]}->{nums[-1]}" if l != len(nums) - 1 else f"{nums[-1]}")
+        return res

Hard/29.py

@@ -0,0 +1,26 @@
+class Solution:
+    def calculate(self, s: str) -> int:
+        stack = []
+        result = 0
+        sign = 1
+        num = 0
+
+        for ch in s:
+            if ch.isdigit():
+                num = num * 10 + int(ch)
+            elif ch in "+-":
+                result += sign * num
+                num = 0
+                sign = 1 if ch == "+" else -1
+            elif ch == "(":
+                stack.append(result)
+                stack.append(sign)
+                result = 0
+                sign = 1
+            elif ch == ")":
+                result += sign * num
+                num = 0
+                result *= stack.pop()
+                result += stack.pop()
+
+        return result + sign * num

Medium/260.py

@@ -0,0 +1,20 @@
+from typing import List
+
+
+class Solution:
+    def singleNumber(self, nums: List[int]) -> List[int]:
+        res = 0
+        for num in nums:
+            res = res ^ num
+
+        diff_bit = 1
+        while not (res & diff_bit):
+            diff_bit <<= 1
+
+        a, b = 0, 0
+        for n in nums:
+            if diff_bit & n:
+                a = a ^ n
+            else:
+                b = b ^ n
+        return [a, b]

Medium/452.py

@@ -0,0 +1,20 @@
+from typing import List
+
+
+class Solution:
+    def findMinArrowShots(self, points: List[List[int]]) -> int:
+        if not points:
+            return 0
+
+        # Sort balloons by their ending coordinate
+        points.sort(key=lambda x: x[1])
+        arrows = 1
+        end = points[0][1]
+
+        for x_start, x_end in points[1:]:
+            if x_start > end:
+                # Need a new arrow
+                arrows += 1
+                end = x_end  # update arrow position
+
+        return arrows

Medium/71.py

@@ -0,0 +1,16 @@
+class Solution:
+    def simplifyPath(self, path: str) -> str:
+        components = path.split("/")
+        st = []
+
+        for comp in components:
+            if comp == "" or comp == ".":
+                continue
+
+            if comp == "..":
+                if st:
+                    st.pop()
+            else:
+                st.append(comp)
+
+        return "/" + "/".join(st)

README.md

@@ -17,15 +17,15 @@ This repository contains my solutions to various LeetCode problems. Each solutio
 
 ### Easy Problems
 
-- **Total Solved:** [45]
+- **Total Solved:** [46]
 
 ### Medium Problems
 
-- **Total Solved:** [116]
+- **Total Solved:** [118]
 
 ### Hard Problems
 
-- **Total Solved:** [28]
+- **Total Solved:** [29]
 
 ## 🛠️ Languages Used