Chương trình N! rất lớn(N2000)

[nthung]

Chào các bạn minh show hàng chương trình tính N! với N<2000 nó mới chỉ là V1 thôi

// Mult_Big_Int.cpp : Defines the entry point for the console application.// #include "stdafx.h"#include<stdio.h>#include<math.h>#include<conio.h>#include<string.h> #define MAX 100000 int a[4],b[2*MAX];int n,leng=0,lengb=0;/*********************************************/void input();void Convert(int c[],int y);void Print();/*********************************************/void Print(){int i;int newline=0;FILE*f=fopen("KetQua.txt","w");for(i=0;i<=lengb;i++){    newline++;printf("%d",b[lengb-i]);fprintf(f,"%d",b[lengb-i]);if(newline==75){fprintf(f,"\n");newline=0;}}}void input(){    printf("Chuong tring tinh n!\n");    printf("N=");scanf("%d",&n);    }/*********************************************/void Mang(int n){    leng=0;    while(n>0){    a[leng]=n%10;    n=n/10;    leng++;    }    leng--;} /*********************************************/void Multi(int a[],int n,int b[],int m){ int i,j,k;int c[2*MAX]; for(k=0;k<=m+n;k++)c[k]=0;for(i=0;i<=n;i++)for(j=0;j<=m;j++)for(k=0;k<=m+n;k++)if(i+j==k){    c[k]=c[k]+a[i]*b[j];}for(i=0;i<=m+n;i++)b[i]=c[i];Convert(b,m+n);}/*********************************************/void Convert(int c[],int m){int i,h; for(i=0;i<m;i++){    c[i+1]=c[i+1]+c[i]/10;    c[i]=c[i]%10;}h=m;if(c[m]>9){    int x;    x=c[m];c[m]=x%10;c[m+1]=x/10;h=m+1;}lengb=h;}/*********************************************/ /*********************************************/void main(){            int i;    b[lengb]=1;    input(); for(i=2;i<=n;i++){    Mang(i);Multi(a,leng,b,lengb);}Print();     getch();    }

[lelinhcntt]

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