wlq484906073 @ 2022-10-23 18:52:02
#include<stdio.h>
int main()
{
int n,t=1,s=0;
scanf("%d",&n);
for(int i=1;i<=n;i++){
t=t*i;
s=s+t;
}
printf("%d\n",s);
return 0;
}by _djc_ @ 2022-10-23 18:53:21
因为要用高精……
by RichardCgy @ 2022-10-23 19:00:03
拿出来了压箱底的高精度模板
#include <cstdio>
#include <string>
#include <iostream>
#include <algorithm>
using namespace std;
class BigInt//所有数字都需要是正整数
{
public:
int value[1000];//1为个位，2为十位，...
int size=0;
void clear()
{
for(int i=0;i<=999;i++)
value[i]=0;
size=1;
}
BigInt()//创建时自动清空
{
for(int i=1;i<=999;i++)
value[i]=0;
size=1;
}
BigInt(BigInt* a)
{
for(int i=1;i<=a->size;i++)
value[i]=a->value[i];
size=a->size;
}
BigInt(long long a)
{
clear();
size=1;
while(a>0)
{
value[size]=a%10;
size++;
a/=10;
}
size--;
}
void print()//输出
{
if(size==0)
{
std::printf("%d",0);
return;
}
for(int i=size;i>=1;i--)
std::printf("%d",value[i]);
}
void read()
{
string a;
cin>>a;
for(int i=a.length()-1;i>=0;i--)
{
this->value[a.length()-i]=a[i]-'0';
}
this->size=a.length();
}
BigInt add(BigInt a,BigInt b)
{
int cnt=a.size;
if(cnt<b.size)
cnt=b.size;
BigInt ans;
for(int i=1;i<=cnt;i++)
{
ans.value[i]+=a.value[i]+b.value[i];
ans.value[i+1]+=ans.value[i]/10;
ans.value[i]%=10;
}
ans.size=cnt;
if(ans.value[cnt+1]!=0)
ans.size++;
return ans;
}
int big_number_cmp(BigInt a,BigInt b)//0相等,1左大于右,2右大于左
{
if(b.value[b.size]>=0&&a.value[a.size]<0)
return 2;
if(a.size!=b.size)
{
if(a.size>b.size)
return 1;
return 2;
}
for(int i=a.size;i>=1;i--)
{
if(a.value[i]!=b.value[i])
{
if(a.value[i]>b.value[i])
return 1;
return 2;
}
}
return 0;
}
int operator =(int other)//赋值给高精度数据
{
int a=other;
size=1;
while(other>0)
{
value[size]=other%10;
other/=10;
size++;
}
size--;
return a;
}
BigInt operator +(BigInt b)//高精加!
{
int cnt=this->size;
if(cnt<b.size)
cnt=b.size;
BigInt ans;
for(int i=1;i<=cnt;i++)
{
ans.value[i]+=this->value[i]+b.value[i];
ans.value[i+1]+=ans.value[i]/10;
ans.value[i]%=10;
}
ans.size=cnt;
if(ans.value[cnt+1]!=0)
ans.size++;
return ans;
}
BigInt operator -(BigInt b)//高精减!
{
int cnt=this->size;
if(big_number_cmp(this,b)==2)
{
cerr<<"在减法中结果出现负数\n";
exit(1001);
}
else if(big_number_cmp(this,b)==0)
{
BigInt ans;
return ans;
}
BigInt ans;
for(int i=1;i<=cnt;i++)
{
ans.value[i]=this->value[i]-b.value[i];
}
for(int i=1;i<=cnt;i++)
{
if(ans.value[i]<0)
{
ans.value[i+1]--;
ans.value[i]+=10;
}
}
for(int i=cnt;i>=1;i--)
{
if(ans.value[i]!=0)
{
ans.size=i;
break;
}
}
return ans;
}
BigInt multiply_(BigInt a,int b)//b=0~10,单位高精乘
{
BigInt ans;
if(b==0)
{
return ans;
}
if(b==10)
{
for(int i=1;i<=a.size;i++)
ans.value[i+1]=a.value[i];
ans.size=a.size+1;
return ans;
}
for(int i=1;i<=a.size;i++)
ans.value[i]=a.value[i]*b;
for(int i=1;i<=a.size;i++)
{
if(ans.value[i]>=10)
{
ans.value[i+1]+=ans.value[i]/10;
ans.value[i]%=10;
}
}
for(int i=999;i>=1;i--)
{
if(ans.value[i]!=0)
{
ans.size=i;
break;
}
}
if(ans.size==0)
ans.size=1;
return ans;
}
BigInt multiply(BigInt a,BigInt b)
{
BigInt ans;
for(int i=1;i<=a.size;i++)
{
BigInt temp;
temp=multiply_(b,a.value[i]);//this因为一些奇妙的特性不是正常变量，而是指针，指针入参太难懂不易调试了
for(int j=i;j<=i+temp.size-1;j++)
ans.value[j]+=temp.value[j-i+1];
}
for(int i=1;i<=999;i++)
{
if(ans.value[i]>=10)
{
ans.value[i+1]+=ans.value[i]/10;
ans.value[i]%=10;
}
}
for(int i=999;i>=1;i--)
{
if(ans.value[i]!=0)
{
ans.size=i;
break;
}
}
if(ans.size==0)
ans.size=1;
return ans;
}
BigInt divicion(BigInt a,BigInt b)
{
BigInt ans;
BigInt del;
int cnt=1;
del=b;
while(big_number_cmp(a,del)==1)
{
del=multiply_(del,10);
cnt++;
}
cnt--;
for(int i=1;i<=del.size;i++)
{
del.value[i]=del.value[i+1];
}
del.size--;
ans.size=cnt;
while(big_number_cmp(a,b)!=2)
{
if(big_number_cmp(a,del)!=2)
{
//进行高精减...
for(int i=1;i<=a.size;i++)
a.value[i]-=del.value[i];
for(int i=1;i<=a.size;i++)
if(a.value[i]<0)
{
a.value[i]+=10;
a.value[i+1]--;
}
for(int i=999;i>=1;i--)
{
if(a.value[i]!=0)
{
a.size=i;
break;
}
}
ans.value[cnt]++;
}
else
{
cnt--;
for(int i=1;i<=del.size;i++)
{
del.value[i]=del.value[i+1];
}
del.size--;
}
}
return ans;
}
BigInt minus(BigInt a,BigInt b)
{
int cnt=a.size;
if(big_number_cmp(a,b)==2)
{
cerr<<"在减法中结果出现负数\n";
exit(1001);
}
else if(big_number_cmp(a,b)==0)
{
BigInt ans;
return ans;
}
BigInt ans;
for(int i=1;i<=cnt;i++)
{
ans.value[i]=a.value[i]-b.value[i];
}
for(int i=1;i<=cnt;i++)
{
if(ans.value[i]<0)
{
ans.value[i+1]--;
ans.value[i]+=10;
}
}
for(int i=cnt;i>=1;i--)
{
if(ans.value[i]!=0)
{
ans.size=i;
break;
}
}
return ans;
}
BigInt mod(BigInt this_,BigInt other)
{
BigInt quotient/*商*/=divicion(this_,other);
BigInt ans;
ans=minus(this_,multiply(quotient,other));
return ans;
}
BigInt operator *(BigInt b)//高精乘!
{
BigInt ans;
for(int i=1;i<=this->size;i++)
{
BigInt temp;
temp=multiply_(b,this->value[i]);//this因为一些奇妙的特性不是正常变量，而是指针，指针入参太难懂不易调试了
for(int j=i;j<=i+temp.size-1;j++)
ans.value[j]+=temp.value[j-i+1];
}
for(int i=1;i<=999;i++)
{
if(ans.value[i]>=10)
{
ans.value[i+1]+=ans.value[i]/10;
ans.value[i]%=10;
}
}
for(int i=999;i>=1;i--)
{
if(ans.value[i]!=0)
{
ans.size=i;
break;
}
}
if(ans.size==0)
ans.size=1;
return ans;
}
BigInt operator /(BigInt other)//高精除!除为整除不保留余数
{
BigInt ans;
BigInt del;
int cnt=1;
del=other;
while(big_number_cmp(this,del)==1)
{
del=multiply_(del,10);
cnt++;
}
cnt--;
for(int i=1;i<=del.size;i++)
{
del.value[i]=del.value[i+1];
}
del.size--;
ans.size=cnt;
while(big_number_cmp(this,other)!=2)
{
if(big_number_cmp(this,del)!=2)
{
//进行高精减...
for(int i=1;i<=this->size;i++)
this->value[i]-=del.value[i];
for(int i=1;i<=this->size;i++)
if(this->value[i]<0)
{
this->value[i]+=10;
this->value[i+1]--;
}
for(int i=999;i>=1;i--)
{
if(this->value[i]!=0)
{
this->size=i;
break;
}
}
ans.value[cnt]++;
}
else
{
cnt--;
for(int i=1;i<=del.size;i++)
{
del.value[i]=del.value[i+1];
}
del.size--;
}
}
return ans;
}
BigInt operator %(BigInt other)
{
BigInt quotient/*商*/=divicion(this,other);
BigInt ans;
ans=minus(this,multiply(quotient,other));
return ans;
}
BigInt operator +=(BigInt other)
{
for(int i=1;i<=max(this->size,other.size);i++)
{
this->value[i]+=other.value[i];
}
for(int i=1;i<=max(this->size,other.size);i++)
{
if(this->value[i]>=10)
{
this->value[i]-=10;
this->value[i+1]++;
}
}
return this;
}
BigInt operator -=(BigInt other)
{
for(int i=1;i<=max(this->size,other.size);i++)
{
this->value[i]-=other.value[i];
}
for(int i=1;i<=max(this->size,other.size);i++)
{
if(this->value[i]<0)
{
this->value[i]+=10;
this->value[i+1]--;
}
}
return this;
}
BigInt operator *=(BigInt other)
{
BigInt ans;
for(int i=1;i<=this->size;i++)
{
BigInt temp;
temp=multiply_(other,this->value[i]);//this因为一些奇妙的特性不是正常变量，而是指针，指针入参太难懂不易调试了
for(int j=i;j<=i+temp.size-1;j++)
ans.value[j]+=temp.value[j-i+1];
}
for(int i=1;i<=999;i++)
{
if(ans.value[i]>=10)
{
ans.value[i+1]+=ans.value[i]/10;
ans.value[i]%=10;
}
}
for(int i=999;i>=1;i--)
{
if(ans.value[i]!=0)
{
ans.size=i;
break;
}
}
if(ans.size==0)
ans.size=1;
return ans;
}
BigInt operator /=(BigInt other)
{
BigInt ans;
BigInt del;
int cnt=1;
del=other;
while(big_number_cmp(this,del)==1)
{
del=multiply_(del,10);
cnt++;
}
cnt--;
for(int i=1;i<=del.size;i++)
{
del.value[i]=del.value[i+1];
}
del.size--;
ans.size=cnt;
while(big_number_cmp(this,other)!=2)
{
if(big_number_cmp(this,del)!=2)
{
//进行高精减...
for(int i=1;i<=this->size;i++)
this->value[i]-=del.value[i];
for(int i=1;i<=this->size;i++)
if(this->value[i]<0)
{
this->value[i]+=10;
this->value[i+1]--;
}
for(int i=999;i>=1;i--)
{
if(this->value[i]!=0)
{
this->size=i;
break;
}
}
ans.value[cnt]++;
}
else
{
cnt--;
for(int i=1;i<=del.size;i++)
{
del.value[i]=del.value[i+1];
}
del.size--;
}
}
return ans;
}
};BigInt创建高精度类，存储上限10^1000，有完整的计算符号重载，能直接和默认类型数据参与计算（然而这么搞容易wa）.read()读入，.print()输出
by _wjr_ @ 2022-10-23 19:04:01
楼上正解