Coding challenges for code review

src/brain_teasers/python/add_string_numbers/src/add_string_numbers.py

@@ -0,0 +1,56 @@
+def add_string_numbers(s1, s2):
+    """
+     a function for adding two string numbers together and returning the result as a string
+     takes in s1 and s2 strings
+     returns final, a string (sum of strings)
+
+    """
+
+    #check if atleast one of the numbers are floats so we can convert
+    if "." not in s1 and "." in s2:
+      s1 += "."
+    if "." not in s2 and "." in s1:
+      s2 += "."
+
+    if  s1 or s2:
+     #check to see how many numbers come after the decimal
+       for i in range(len(s1)):
+          if s1[i] == ".":
+            savedigits1 = len(s1[i+1:(len(s1)-1)])
+            break
+
+       for i in range(len(s2)):
+          if s2[i] == ".":
+            savedigits2 = len(s1[i+1:(len(s2)-1)])
+            break
+
+#check which one has the longest decimal
+    if savedigits1>savedigits2:
+      diff = savedigits1 - savedigits2
+      for i in range(diff):
+            s2 += "0"
+    elif savedigits2>savedigits1:
+       diff = savedigits2 - savedigits1
+       for i in range(diff):
+            s1 += "0"
+    carry = 0
+    result = []
+    # for i in s1[::-1]:
+    #     for h in s2[::-1]:
+#Calculate backwards with carry
+    for i in range(len(s1)-1,-1,-1):
+      if s1[i]==".":
+          result.insert(0,'.')
+          continue
+
+      num1 = int(s1[i])
+      num2 = int(s2[i])
+
+      calc = num1 + num2 +carry
+      carry = calc//10
+      result.insert(0,str(calc%10))
+    if carry:
+      result.insert(0, str(carry))
+    final = ''.join(result)
+
+    return final

src/brain_teasers/python/subarray_sum/src/subarray_sum.py

@@ -0,0 +1,16 @@
+def subarray_sum(array, start, end):
+    """
+    function that iterates through the subarray and calculates the sum of elements
+    returns (ans) an interger (sum of sub array)
+    """
+    # get indexes of the start and end
+    storeStartId = array.index(start)
+    storeEndId = array.index(end)
+    ans = 0
+    # add the numbers 
+    for i in range(start, end):
+        if array[i] == start:
+            continue
+        else:
+           ans += array[i]
+    return ans

src/dynamic_programming/python/fibonacci/src/fib.py

@@ -1,4 +1,5 @@
 def fib_basic(n):
+
     if n <= 0:
         return 0
     elif n == 1:
@@ -8,6 +9,7 @@ def fib_basic(n):
 
 
 def fib_memo(n, memo=dict()):
+
     if n < 1:
         return 0
     if n <= 2:
@@ -16,6 +18,7 @@ def fib_memo(n, memo=dict()):
 
 
 def fib_tab(n):
+
     if n < 1:
         return 0
 
@@ -29,3 +32,58 @@ def fib_tab(n):
         table[i] = table[i - 1] + table[i - 2]
 
     return table[n]
+
+####
+### Gloire
+def fib_basic(n):
+    """
+     This is a recursive function that finds the nth number in the Fibonacci sequence by recursively 
+     calculating the
+     (n-1) and (n-2)th numbers in the sequence
+     returns fib(n)
+    """
+    if n == 0 :
+        return 0
+    elif n == 1:
+        return 1
+    else:
+        return fib_basic(n-1)+ fib_basic(n-2)
+
+#fibdic = {}
+def fib_memo(n, memo = {}):
+    """
+    This function uses memoization to store the results of subproblems and avoid recalculating them.
+    It works similarly to the fib_basic() function, but it uses a dictionary to store the results of subproblems
+    so that they can be reused in future recursive calls.
+    returns the fib(n)
+
+    """
+    if n == 0 :
+        return 0
+    elif n == 1:
+        return 1
+    try:
+        return memo[n]
+    except KeyError:
+        result = fib_memo(n-1, memo) + fib_memo(n-2, memo) 
+        memo[n] = result 
+        return result
+
+def fib_tab(n):
+    """
+    This function uses dynamic programming to store the results of subproblems in a table.
+    It iteratively calculates the nth number in the Fibonacci sequence by using the values of the (n-1)th
+    and $(n - 2)th $numbers in the sequence
+    returns a list of fib numbers
+    """
+
+    if n<= 1:
+        return n
+
+    table = [0] * (n+1)
+    table[1] = 1
+
+    for i in range(2,n+1):
+        table[i] = table[i-1]+table[i-2]
+
+    return table

src/sorting/python/insertion_sort/src/insertion_sort.py

@@ -0,0 +1,11 @@
+def insertionsort(li):
+    """
+    Sorts items in a list (li) and returns a sorted list(ascending order)
+
+    """
+    for i in range(1, len(li)):
+        k = i
+        while li[k-1]>li[k] and k>0:
+            li[k],li[k-1] = li[k-1],li[k]
+            k -= 1
+    return li

src/sorting/python/selection_sort/src/selection_sort.py

@@ -0,0 +1,10 @@
+def selectionsort_v1(li):
+    """
+    Sorts items in a list (li) and returns a sorted list (li)(ascending order)
+    """
+    for i in range(len(li)):
+        minid = i
+        for j in range(i+1,len(li)):
+            minid = j
+        li[i],li[minid] = li[minid],li[i]
+    return li