Adding Warnup-2

Author: Jem Chang

README.md

@@ -1,6 +1,6 @@
 ## Practicing Python Programming in [CodingBat](http://codingbat.com/python)
-1. Warmup-1
-2. Warmup-2
+1. [Warmup-1](https://github.com/jemc36/CodingBat-Python/tree/master/Warmup-1)
+2. [Warmup-2](https://github.com/jemc36/CodingBat-Python/tree/master/Warmup-2)
 3. Logic-1
 4. Logic-2
 5. String-1

Warmup-1/.DS_Store

@@ -0,0 +1,9 @@
+"""
+Given an array of ints, return True if the sequence of numbers 1, 2, 3 appears in the array somewhere.
+"""
+def array123(nums):
+  for i in range(len(nums)-2):
+    if nums[i:i+3]== [1,2,3]:
+      return True
+    else:continue
+  return False

Warmup-2/array123.py

@@ -0,0 +1,10 @@
+"""
+Given an array of ints, return the number of 9's in the array.
+"""
+def array_count9(nums):
+  count9 = int()
+  for i in nums:
+    if i == 9:
+      count9 = count9 + 1
+    else: continue
+  return count9

Warmup-2/array_count9.py

@@ -0,0 +1,16 @@
+"""
+Given an array of ints, return True if one of the first 4 elements in the array is a 9.
+The array length may be less than 4.
+"""
+def array_front9(nums):
+  num4 = list()
+  if len(nums) < 4:
+    for i in nums:
+      if i !=9:continue
+      return True
+  else:
+    num4 = nums[0:4]
+    for j in num4:
+      if j !=9: continue
+      return True
+  return False

Warmup-2/array_front9.py

@@ -0,0 +1,15 @@
+"""
+Given a string and a non-negative int n,
+we'll say that the front of the string is the first 3 chars,
+or whatever is there if the string is less than length 3. Return n copies of the front;
+"""
+def front_times(x, n):
+  a = str()
+  allstr = str()
+  if len(x) < 3:
+    a = x
+  else:
+    a = x[0:3]
+  for i in range(n):
+    allstr = allstr + a
+  return allstr

Warmup-2/front_times.py

@@ -0,0 +1,14 @@
+"""
+Given a string, return the count of the number of times
+that a substring length 2 appears in the string and
+also as the last 2 chars of the string, so "hixxxhi" yields 1
+(we won't count the end substring).
+"""
+def last2(x):
+  last2 = x[-2:]
+  count = int()
+  for i in range(len(x)-2):
+    if x[i:i+2] == last2:
+      count = count + 1
+    else: continue
+  return count

Warmup-2/last2.py

@@ -0,0 +1,12 @@
+"""
+Given a string, return a new string made of every other char starting with the first,
+so "Hello" yields "Hlo".
+"""
+def string_bits(x):
+  allstr = str()
+  for i in range(len(x)):
+    if i % 2 == 0:
+      allstr = allstr + x[i]
+    else:
+      allstr = allstr
+  return allstr

Warmup-2/string_bits.py

@@ -0,0 +1,12 @@
+"""
+Given 2 strings, a and b, return the number of the positions where they
+contain the same length 2 substring. So "xxcaazz" and "xxbaaz" yields 3,
+since the "xx", "aa", and "az" substrings appear in the same place in both strings.
+"""
+def string_match(a, b):
+  count = int()
+  for i in range(len(a)-1):
+    if a[i:i+2] == b[i:i+2]:
+      count = count + 1
+    else: continue
+  return count

Warmup-2/string_match.py

@@ -0,0 +1,9 @@
+"""
+Given a non-empty string like "Code" return a string like "CCoCodCode".
+"""
+
+def string_splosion(x):
+  all = str()
+  for i in range(len(x)):
+    all = all + x[0:i+1]
+  return all

Warmup-2/string_splosion.py

@@ -0,0 +1,9 @@
+"""
+Given a string and a non-negative int n,
+return a larger string that is n copies of the original string.
+"""
+def string_times(x, n):
+  allstr = str()
+  for i in range(n):
+    allstr = allstr + x
+  return allstr