haoyelll @ 2022-12-04 20:36:07
#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
int main()
{
int n, a[1001] = { 1 }, b[1001] = { 1 }, i, j;
scanf("%d", &n);
for (i = 2; i <= n; i++)
{
for (j = 0; j <= i; j++)
b[j] *= i;
for (j = 0; j <= i; j++)
{
if (b[j] >9)
{
b[j + 1] += b[j] / 10;
b[j] %= 10;
}
}
for (j = 0; j <= i; j++)
{
a[j] += b[j];
if (a[j] >9)
{
a[j + 1] += a[j] / 10;
a[j] %= 10;
}
}
}
for (i;i>0&& a[i] == 0; i--)
for (j = i; j >= 0; j--)
printf("%d",a[j]);
return 0;
}by 安舒阳 @ 2022-12-04 20:40:08
@haoyelll 因为你需要在输出中去掉这些0
by haoyelll @ 2022-12-04 20:51:02
@安舒阳 大概懂了，谢谢大佬
by ysxkrs @ 2022-12-04 21:05:11
高精度乘法你可能还有一些不太懂，可以复习一下
by ysxkrs @ 2022-12-04 21:12:52
本蒟蒻的伪代码，仅供参考，勿喷
int a[], alen ;
int b[], blen ;
int ans[], anslen = alen + blen ;
for ( int i = 1, x; i <= alen; i ++ )
x = 0 ;
for ( int j = 1; j <= blen; j ++ )
ans[i + j - 1] += a[i] * b[i] + x ;
x = ans[i + j - 1] / 10 ;
ans[i + j - 1] %= 10 ;
ans[blen + i] = x ;
while ( ans[anslen] == 0 && anslen > 0 ) anslen -- ;by ysxkrs @ 2022-12-04 21:23:51
参考博客
by haoyelll @ 2022-12-04 22:31:54
@xhlmrdr 好的，谢谢大佬