UVA - 10916 Factstone Benchmark

题目大意：求计算计算机的进制所能表示的最多的n的阶乘

解题思路：2的n次方会溢出，两边同时取对数再计算，2^word = n!,取对数得，word = log(2)1 + ... + log(2)n，换底公式log(n)m = lg(m) / lg(n)

#include<cstdio>#include<cmath>int main() {int year;while(scanf("%d", &year) && year) {if(year == 0)break;year = year - 1960;year = (year - year % 10) / 10;int  word = 4;for(int i = 1; i <= year; i++)word = word * 2;int ans = 1;double temp = 0;while(1) {temp =  temp + log(ans) / log(2);if(temp >= word)break;elseans++;}printf("%d\n", ans - 1);}return 0;}