11 lines
178 B
C++
11 lines
178 B
C++
#include <malloc.h>
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#include <stdint.h>
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#include <stdio.h>
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int main() {
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uint64_t n;
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scanf("%d", &n);
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double p = (n - 1) * (n) / (double) 4;
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printf("%f\n", p);
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} |