#include<stdio.h>
int f(int x);
unsigned long long j(int x);
int main()
{
int n;
scanf("%d",&n);
f(n);
return 0;
}
int f(int x)
{
int i;
unsigned long long sum=0;
for(i=1;i<=x;i++)
{sum+=j(i);
}
printf("%llu",sum);
return 0;
}
unsigned long long j(int x)
{int i;
unsigned long long ret=1;
for(i=1;i<=x;i++)
{ret*=i;
}
return ret;
}
阶乘递归
标签：return,29.1208,int,sum,unsigned,long,ret From： https://blog.51cto.com/u_15758636/5926639