26 lines
387 B
Python
26 lines
387 B
Python
'''
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【程序25】
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题目：求1+2!+3!+...+20!的和
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1.程序分析：此程序只是把累加变成了累乘。
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2.程序源代码：
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'''
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#方法一
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n = 0
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s = 0
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t = 1
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for n in range(1,21):
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t *= n
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s += t
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print '1! + 2! + 3! + ... + 20! = %d' % s
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#方法二
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s = 0
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l = range(1,21)
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def op(x):
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r = 1
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for i in range(1,x + 1):
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r *= i
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return r
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s = sum(map(op,l))
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print '1! + 2! + 3! + ... + 20! = %d' % s
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