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Diffstat (limited to 'scratch/facebook/language2.py')
-rw-r--r-- | scratch/facebook/language2.py | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/scratch/facebook/language2.py b/scratch/facebook/language2.py new file mode 100644 index 000000000000..3aebd454833b --- /dev/null +++ b/scratch/facebook/language2.py @@ -0,0 +1,50 @@ + + + + + + + + + +def tokenize(xs): + result = [] + i = 0 + while i < len(xs): + curr = xs[i] + if curr in {'*','+'}: + result.append(curr) + i += 1 + continue + i += 1 + while i < len(xs) and xs[i] in {str(x) for x in range(10)}: + curr += xs[i] + i += 1 + result.append(int(curr)) + return result + +def parse(tokens): + result = [] + series = [] + for token in tokens: + if token == '*': + continue + elif token == '+': + result.append(series) + series = [] + else: + series.append(token) + if series: + result.append(series) + return result + +def product(xs): + result = 1 + for x in xs: + result *= x + return result + +def evaluate(tree): + return sum([product(xs) for xs in tree]) + +print(evaluate(parse(tokenize("2+30*8*9+10")))) |