Zpy123 @ 2025-01-10 17:59:25

#include<bits/stdc++.h>
using namespace std;
int main(){
    int n,m,s;
    s=0;
    cin>>n;
    for(int i=1;i<=n;i++){
        m=1;
        for(int j=1;j<=i;j++){
            m=j*m;
        }
        s=s+m;
    }
    cout<<s;
}

cin>>n;
for(int i=1;i<=n;i++){
    m=1;
    for(int j=1;j<=i;j++){
        m=j*m;
    }
    s=s+m;
}
cout<<s;

by Hua_Tian @ 2025-01-10 18:44:23

哥，这是高精度，请看以下代码：

#include<bits/stdc++.h>
using namespace std;
int a[100000],n,i,y,xy[100000],s[100000];
void add(){
    int i;
    memset(xy,0,sizeof(xy));
    xy[0]=max(s[0],a[0]);
    for (i=1;i<=xy[0];i++){
        xy[i]+=s[i]+a[i];
        xy[i+1]=xy[i]/10;
        xy[i]%=10;
     }
    while (xy[xy[0]+1]>0){
            xy[xy[0]+2]=xy[xy[0]+1]/10;
            xy[xy[0]+1]%=10;
            xy[0]++;
        }
    s[0]=xy[0];
    for (i=1;i<=xy[0];i++) s[i]=xy[i];
}
int main()
{
    cin>>n;
    a[0]=1;
    a[1]=1;
    s[0]=1;
    s[1]=0;
    for (y=1;y<=n;y++){
        memset(xy,0,sizeof(xy));
        xy[0]=a[0];
        for (i=1;i<=a[0];i++){
          xy[i]+=a[i]*y;
          xy[i+1]=xy[i]/10;
          xy[i]%=10;
        }
        while (xy[xy[0]+1]>0){
            xy[xy[0]+2]=xy[xy[0]+1]/10;
            xy[xy[0]+1]%=10;
            xy[0]++;
        }
        for (i=1;i<=xy[0];i++) a[i]=xy[i];
        a[0]=xy[0];
        add();
    }
    for (i=s[0];i>=1;i--)cout<<s[i];
    return 0;
}

by chenxitao @ 2025-01-10 19:19:06

#include<bits/stdc++.h>
using namespace std;
int n,a[90],b[90],c[90],f[90],d,x,y=1,z=1,l,m=1;
string s;
int main(){
    cin>>n;
    b[0]=1;
    for(int i=1;i<=n;i++){
        x=0;
        int p=i;
        while(p>0){
            a[x++]=p%10;
            p/=10;
        }
        for(int j=0;j<x;j++)for(int k=0;k<=y;k++)c[j+k]+=a[j]*b[k];
        for(int j=0;j<z;j++)if(c[j]>9)c[j+1]+=c[j]/10,c[j]%=10;
        if(c[z])z++;
        l=y,y=z,m=max(m,z);
        for(int k=z-1;k>=0;k--) b[k]=c[k];
        z=x+l;
        memset(c,0,sizeof(c));
        for(int j=0;j<m;j++){
            f[j]+=b[j];
            if(f[j]>9)f[j+1]+=f[j]/10,f[j]%=10;
        }
    }
    while(!f[m]&&m>0)m--;
    for(int i=m;i>=0;i--)cout<<f[i];
    return 0;
}

by Hkueen @ 2025-01-10 19:23:51

@Zpy123悬棺是本好书啊