added more files

InterviewProblems/ThreeSum.py

@@ -0,0 +1,87 @@
+from typing import List
+
+"""
+# brute force solution --> gives Time Limit Exceeded error for lengthier list
+def threeSum(nums: List[int]) -> List[List[int]]:
+    innerlist = []
+    outerlist = []
+    if len(nums) > 3:
+        nums.sort()
+        for i in range(len(nums) - 2):
+            for j in range(i+1,len(nums) - 1):
+                for k in range(j+1,len(nums)):
+                    innerlist = []
+                    if nums[i] + nums[j] + nums[k] == 0:
+                        innerlist.append(nums[i])
+                        innerlist.append(nums[j])
+                        innerlist.append(nums[k])
+                        if innerlist not in outerlist:
+                            outerlist.append(innerlist)
+        return outerlist
+    elif len(nums) == 3:
+        if sum(nums) == 0:
+            innerlist = nums.copy()
+            outerlist.append(innerlist)
+            return outerlist
+        else:
+            return [] 
+    else:
+        return []
+"""
+"""
+# another approach
+def threeSum(nums: List[int]) -> List[List[int]]:
+    outerlist = []
+    threesum = 0
+    if len(nums) > 3:
+        nums.sort()
+        for i in range(len(nums) - 2):            
+            if i > 0 and nums[i] == nums[i - 1]:
+                continue
+            j,k = i+1,len(nums)-1
+            print(j,k)
+            while j < k:
+                threesum = nums[i] + nums[j] + nums[k]
+                if threesum == 0:
+                    outerlist.append([nums[i],nums[j],nums[k]])
+                    k = k - 1
+                    while j < k and nums[k] == nums[k + 1]:
+                        k = k - 1
+                elif threesum > 0:
+                    k = k - 1
+                else:
+                    j = j + 1
+        return outerlist
+    elif len(nums) == 3:
+        if sum(nums) == 0:
+            outerlist.append(nums)
+            return outerlist
+        else:
+            return [] 
+    else:
+        return []
+"""
+def threeSum(nums: List[int]) -> List[List[int]]:
+        outerlist = []
+        threesum = 0
+        for i in range(len(nums) - 2):  
+            nums.sort()
+            if i > 0 and nums[i] == nums[i - 1]:
+                continue
+            j,k = i+1,len(nums)-1
+            while j < k:
+                threesum = nums[i] + nums[j] + nums[k]
+                if threesum == 0:
+                    outerlist.append([nums[i],nums[j],nums[k]])
+                    k = k - 1
+                    while j < k and nums[k] == nums[k + 1]:
+                        k = k - 1
+                elif threesum > 0:
+                    k = k - 1
+                else:
+                    j = j + 1
+        return outerlist
+
+print(threeSum([0,0,0]))
+
+print(threeSum([-1,0,1,2,-1,-4]))

InterviewProblems/fourSum.py

@@ -0,0 +1,69 @@
+from typing import List
+"""
+Given an array nums of n integers, return an array of all the unique quadruplets [nums[a], nums[b], nums[c], nums[d]] such that:
+
+0 <= a, b, c, d < n
+a, b, c, and d are distinct.
+nums[a] + nums[b] + nums[c] + nums[d] == target
+You may return the answer in any order.
+"""
+"""
+# brute force solution
+def fourSum(nums: List[int], target: int) -> List[List[int]]:
+    outerlist = []
+    totalSum = 0
+    if len(nums) > 4:
+        nums.sort()
+        for a in range(len(nums) - 3):
+            for b in range(a+1,len(nums) -2):
+                for c in range(b+1,len(nums) -1):
+                    for d in range(c+1,len(nums)):
+                        totalSum = nums[a] + nums[b] + nums[c] + nums[d]
+                        if totalSum ==  target:
+                            innerlist = [nums[a],nums[b],nums[c],nums[d]]
+                            if innerlist not in outerlist:
+                                outerlist.append(innerlist)
+        return outerlist
+    elif len(nums) == 4:
+        if sum(nums) == target:
+            outerlist.append(nums)
+            return outerlist
+        else:
+            return []
+    else:
+        return []
+"""
+def fourSum(nums: List[int], target: int) -> List[List[int]]:
+    outerlist = []
+    totalSum = 0
+    if len(nums) > 4:
+        nums.sort()
+        for a in range(len(nums) - 3):
+            for b in range(a+1,len(nums) - 2):
+                if a > 0 and nums[a] == nums[a - 1]:
+                    continue
+                (c,d) = (b+1,len(nums) -1)
+                while c < d:
+                    totalSum = nums[a] + nums[b] + nums[c] + nums[d]
+                    if totalSum ==  target:
+                        innerlist = [nums[a],nums[b],nums[c],nums[d]]
+                        if innerlist not in outerlist:
+                            outerlist.append(innerlist)
+                    if totalSum > target:
+                        d = d -1
+                    else:
+                        c = c + 1
+        return outerlist           
+    elif len(nums) == 4:
+        if sum(nums) == target:
+            outerlist.append(nums)
+            return outerlist
+        else:
+            return []
+    else:
+        return []
+
+
+print(fourSum([1,0,-1,0,-2,2],0))
+
+print(fourSum([2,2,2,2,2],8))

InterviewProblems/lengthOfLongestSubstring.py

@@ -0,0 +1,37 @@
+"""
+Given a string s, find the length of the longest substring without repeating characters.
+"""
+def lengthOfLongestSubstring(s: str) -> int:
+        outStr = ""
+        strLength = 0
+        i = 0
+        if len(s) > 1:
+            while i < len(s):
+                if i < len(s) - 1:
+                    if s[i] == s[i+1]:
+                        i = i + 1
+                        if s[i] not in outStr:
+                            outStr = outStr + s[i]
+                    else:
+                        if s[i] not in outStr:
+                            outStr = outStr + s[i]
+                        else:
+                            outStr = ""
+                            outStr = outStr + s[i]
+                        i = i + 1
+            return len(outStr)
+        else:
+            return len(s)
+
+print(lengthOfLongestSubstring("abcabcbb"))
+
+print(lengthOfLongestSubstring("bbbbb"))
+"""
+print(lengthOfLongestSubstring("pwwkew"))
+
+print(lengthOfLongestSubstring(" "))
+
+print(lengthOfLongestSubstring("au"))
+
+print(lengthOfLongestSubstring("dvdf"))
+"""

InterviewProblems/longestPalindrome.py

@@ -0,0 +1,20 @@
+
+
+def longestPalindrome(s: str) -> str:
+        inputstr = ""
+        longestPalindrome = ""
+        for i in range(len(s)):
+            ch_count = s.count(s[i])
+            if ch_count > 1:
+                inputstr = inputstr + s[i]
+                print(inputstr)
+                if len(inputstr) > 1 and inputstr == inputstr[::-1]:
+                    if len(inputstr) > len(longestPalindrome):
+                        longestPalindrome = inputstr
+        return longestPalindrome
+
+#print(longestPalindrome("babad"))
+
+#print(longestPalindrome("cbbd"))
+
+print(longestPalindrome("bdabad"))

InterviewProblems/reverse_Integer.py

@@ -0,0 +1,29 @@
+import sys
+"""
+Given a signed 32-bit integer x, return x with its digits reversed. If reversing x causes the value to go outside the signed 32-bit integer range [-231, 231 - 1], then return 0.
+
+Assume the environment does not allow you to store 64-bit integers (signed or unsigned).
+"""
+def reverse(x: int) -> int:
+        negative = False
+        maxSize = (2 ** 31) - 1
+        minSize = -(2 ** 31)
+        if x < 0:
+            negative = True
+            x = abs(x)
+        xlist = list(map(int,str(x)))
+        xlist.reverse()
+        xoutput = ''.join(map(str,xlist))
+        xoutput = int(xoutput)
+        if negative == True:
+            if -abs(xoutput) < minSize:
+                return 0
+            else:
+                return -abs(xoutput)
+        else:
+            if xoutput > maxSize:
+                return 0
+            else:
+                return xoutput
+
+print(reverse(1534236469))

ToRefer/imp_syntax.py

@@ -21,15 +21,25 @@
 print("Minimum:",maxNum)
 
 lenList =  len(numList)
-print("Length:",lenList)
+print("Length:",lenList) # returns the length of the list
+
+#code to convert int list to interger
+# first convert int list to string and then convert to integer
+
+intNum = ''.join(map(str,numList)) # converts int list to string
+intNum = int(intNum) # convert to integer
+print(intNum)
 
-num = ''.join(numList)
-print(num)
 
 
 text = "hello"
 txtList = list(map(str,text))
 print(txtList)
 
 txt = ''.join(txtList) # joins the list and returns string as output
-print(txt)
+print(txt)
+
+
+# for loop to increment the number by 2
+for i in range(0, 10, 2):
+    print(i)