feat: oct14 level1

python/oct14/level1/maxDigit.py

···
+def maxDigit(n: int) -> int:
+    n = abs(n)
+    d = n % 10
+    r = n // 10
+    next = maxDigit(r) if r > 0 else 0
+    return d if d > next else next
+
+def testMaxDigit():
+    print('Testing maxDigit()...', end='')
+    assert(maxDigit(0) == 0)
+    assert(maxDigit(1) == 1)
+    assert(maxDigit(-1) == 1)
+    assert(maxDigit(12321) == 3)
+    assert(maxDigit(-12321) == 3)
+    assert(maxDigit(102030405060708090) == 9)
+    assert(maxDigit(22222222222) == 2)
+    assert(maxDigit(22222322222) == 3)
+    print('Passed!')
+
+def main():
+    testMaxDigit()
+
+main()

python/oct14/level1/oddCount.py

···
+def oddCount(L: list[int]) -> int:
+    return len([n for n in L if n % 2])
+
+def testOddCount():
+    print('Testing oddCount()...', end='')
+    assert(oddCount([]) == 0)
+    assert(oddCount([1]) == 1)
+    assert(oddCount([2]) == 0)
+    assert(oddCount([1,2,3,4,5,4,3]) == 4)
+    assert(oddCount([1,2,3,4,5,4,3,2]) == 4)
+    assert(oddCount([2,4,6,8,10,12,14]) == 0)
+    assert(oddCount([1,1,1,1,1]) == 5)
+    print('Passed!')
+
+def main():
+    testOddCount()
+
+main()

python/oct14/level1/oddSum.py

···
+def oddSum(L: list[int], sum: int = 0) -> int:
+    if len(L) == 0:
+        return sum
+    val = L[0]
+    rest = L[1:]
+    if val % 2 == 1:
+        sum += val
+    return oddSum(rest, sum)
+
+def testOddSum():
+    print('Testing oddSum()...', end='')
+    assert(oddSum([]) == 0)
+    assert(oddSum([1]) == 1)
+    assert(oddSum([2]) == 0)
+    assert(oddSum([1,2,3,4,5,4,3]) == 12)   # 1+3+5+3
+    assert(oddSum([1,2,3,4,5,4,3,2]) == 12) # 1+3+5+3
+    assert(oddSum([2,4,6,8,10,12,14]) == 0)
+    assert(oddSum([1,1,1,1,1]) == 5) # 1+1+1+1+1
+    print('Passed!')
+
+def main():
+    testOddSum()
+
+main()

python/oct14/level1/reversedEvens.py

···
+def reversedEvens(L: list[int]) -> list[int]:
+    return list(reversed([n for n in L if not (n % 2)]))
+
+def testReversedEvens():
+    print('Testing reversedEvens()...', end='')
+    assert(reversedEvens([]) == [])
+    assert(reversedEvens([1]) == [])
+    assert(reversedEvens([1,2]) == [2])
+    assert(reversedEvens([1,2,3]) == [2])
+    assert(reversedEvens([1,2,3,4]) == [4,2])
+    assert(reversedEvens([1,2,3,4,5,6,5,4,5,6,7]) == [6,4,6,4,2])
+    print('Passed!')
+
+def main():
+    testReversedEvens()
+
+main()

python/oct14/level1/twoHeadsInFiveFlips.py

···
+from random import choice
+
+def flipCoin() -> str:
+    return choice("HT")
+
+def estimateProbability(trials: int) -> float:
+    heads = 0
+    for _ in range(trials):
+        tosses: list[str] = []
+        for _ in range(5):
+            tosses.append(flipCoin())
+        if len([h for h in tosses if h == "H"]) == 2:
+            heads += 1
+    else:
+        return heads / trials
+
+
+def testTwoHeadsInFiveFlipsProblem():
+    print('Testing the twoHeadsInFiveFlips Problem...', end='')
+    trials = 10**5
+    p = estimateProbability(trials)
+    print(p)
+    assert(0.30 <= p <= 0.32) # actual answer is about 0.313
+    print('Passed!')
+
+def main():
+    testTwoHeadsInFiveFlipsProblem()
+
+main()