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https://github.com/Kiritow/OJ-Problems-Source.git
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15 lines
260 B
C++
15 lines
260 B
C++
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#include<stdio.h>
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int n;
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double rev(int c)
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{
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return c <= n ?( ((c & 1) ? 1.0 : -1.0) / c + rev(c + 1) ): 0 ;
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}
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int main()
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{
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int t;
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scanf("%d", &t);
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while (t-- && scanf("%d", &n))
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printf("%.2lf\n", rev(1));
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return 0;
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}
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