Factstone Benchmark

Factstone Benchmark

大意：

根据所给的年份，输出该年计算机最大可以存贮的阶层数N

要点：

使用log()来计算以2为底的阶层的位数；

sum = log2(1) + log2(2) + log2(3) +.....+ log2(n) = log2(n!)；

代码：

#include <stdio.h>#include <cmath>                                                   /*int main(){double sum;for (int i = 4, j = 0; j <= 20; i *= 2, j++){int k = 1;sum = 0;while (sum < i){sum += log2(k);k++;}printf("%d\n", k - 2);}}*/int main(){int year;int ans[21] = { 3, 5, 8, 12, 20, 34, 57, 98, 170, 300, 536, 966, 1754,3210, 5910, 10944, 20366, 38064, 71421, 134480, 254016 };while (scanf("%d", &year) && year != 0){getchar();year = (year - 1960) / 10;printf("%d\n", ans[year]);}return 0;}