大数运算（加减乘除，取模，乘方）
//=============================================================================================================
#include "Big__CALC.h"
int main()
{
char str1[200]="9876543210987";
char str2[200]="1234567890";
char result[200]={0};
printf("str1 = %s\t%d\n",str1,strlen(str1)-1);
printf("str2 = %s\t%d\n",str2,strlen(str2)-1);
int ret = Compare(str1,str2);
if (ret==1)
{
printf("str1 > str2\n");
}
else if(ret==-1) printf("str1 < str2\n");
else printf("str1 = str2\n");
Add(str1,str2,result);
printf("str1 + str2 = %s\t%d\n",result,strlen(result)-1);
Sub(str1,str2,result);
printf("str1 - str2 = %s\t%d\n",result,strlen(result)-1);
Chen(str1,str2,result);
printf("str1 * str2 = %s\t%d\n",result,strlen(result)-1);
char div_result[200]={0};
Mod(str1,str2,result,div_result);
printf("str1 M str2 = %s\t%d\n",result,strlen(result)-1);
printf("str1 / str2 = %s\t%d\n",div_result,strlen(div_result)-1);
int num=10;
char str[200]="999";
ChenFang(str,num,result);
ThrowAway_0(str);
printf("%s ^ %d = %s\t%d\n",str,num,result,strlen(result)-1);
getchar();
return 1;
}
void Trans(char *str_num1, char *str_num2, char *tempbuf1, char *tempbuf2)
{
int len_num1=0;
int len_num2=0;
int i=0;
while(str_num1[i]!='\0')
{
len_num1++;
i++;
}
// printf("字符串1的长度: length1=%d\n",len_num1);
i=0;
while(str_num2[i]!='\0')
{
len_num2++;
i++;
}
// printf("字符串2的长度: length2=%d\n\n",len_num2);
tempbuf1[0]='0';
tempbuf2[0]='0';
//=======================================================================
if(len_num2>=len_num1) //补成相同长度
{
for(i=1;i<=(len_num2-len_num1);i++)
{
tempbuf1[i]='0';
}
for(i=len_num2-len_num1+1;i<=len_num2;i++)
{
tempbuf1[i]=str_num1[i-(len_num2-len_num1+1)];
}
for(i=1;i<=len_num2;i++)
{
tempbuf2[i]=str_num2[i-1];
}
}
//------------------------------------------
else if(len_num2=i+1-len)&&(j<=i);j++)
{
temp[i]+=((int)tempbuf1[len-1-j]-48 )*((int)tempbuf2[len-1-i+j]-48);
}
temp[i]+=jinwei;
if (temp[i]>=10) //&&temp[i]<100
{
jinwei = temp[i]/10;
temp[i] = temp[i]%10;
}
else jinwei=0;
}
else if (i>=len-1)
{
for(j=i-len+2;(j<=len-1)&&(j>=i+1-len)&&(j<=i);j++)
{
temp[i]+=((int)tempbuf1[len-1-j]-48 )*((int)tempbuf2[len-1-i+j]-48);
}
temp[i]+=jinwei;
if (temp[i]>=10) //&&temp[i]<100
{
jinwei = temp[i]/10;
temp[i] = temp[i]%10;
}
else jinwei=0;
}
}
i=max;
while(i>=0)
{
if(temp[i]!=0)
break;
else i--;
}
// printf("str1 * str2= ");
int num=i; // 科学计数法次数
/* for (j=num;j>=0;j--)
{
printf("%d",temp[j]);
}
printf("\t%d\n",num);
*/
//===========================================
memset(result,0,200);
for(i=num;i>=0;i--)
{
result[num-i]=(char)(temp[i]+48);
}
// printf("result = %s\t%d\n",result,strlen(result)-1);
}
//=====================================================================
//extern "C" __declspec(dllexport)
void ChenFang(char *tempbuf1, int num, char *result) // 大数乘方
{
static int count=0;
if (count==0)
{
char c[200]={'1',0,0};
memset(result,0,200);
Chen( tempbuf1 , c , result);
}
count++;
if(num==1)
{
return ;
}
else if(num>1)
{
Chen( tempbuf1 , result , result);
num--;
ChenFang(tempbuf1,num,result);
}
ThrowAway_0 (result);
}
//=================================================
//extern "C" __declspec(dllexport)
void Mod(char *tempbuf1, char *tempbuf2, char *result , char *div_result ) // 大数求余
{
memset(result,0,200);
ThrowAway_0 (tempbuf1);
ThrowAway_0 (tempbuf2);
int max1 = strlen(tempbuf1);
int max2 = strlen(tempbuf2);
int temp=0;
int ret=1;
char div[200]={0};
int count=0;
char AfterSub[200]={0};
if(max1-max2>=0)
{
while(ret==1)
{
Sub (tempbuf1,tempbuf2,AfterSub); //减去之后在判断是否得到结果----即：tempbuf1 < tempbuf2
memset(tempbuf1,0,200);
strcpy (tempbuf1,AfterSub);
ret=Compare(tempbuf1,tempbuf2);
ThrowAway_0 (tempbuf1);
ThrowAway_0 (tempbuf2);
count++;
if(count>=1000)
{
itoa(count,div,10);
Add(div_result,div,div_result);
count=0;
}
}
strcpy (result,tempbuf1);
ThrowAway_0 (result);
itoa(count,div,10);
Add(div_result,div,div_result);
}
else // if (Compare(tempbuf1,tempbuf2)==-1) // 后者大的话，mod 就是 tempbuf1
{
strcpy (result,tempbuf1);
ThrowAway_0 (result);
}
}
//========================================================
//extern "C" __declspec(dllexport)
void Add(char *tempbuf1, char *tempbuf2, char *result) // 大数相加 result = tempbuf1 + tempbuf2
{
char buf1[200]={0};
char buf2[200]={0};
Trans(tempbuf1,tempbuf2,buf1,buf2);
strcpy(tempbuf1,buf1);
strcpy(tempbuf2,buf2);
int i=0;
int temp=0;
int jinwei=0;
int len=0;
while(tempbuf1[i]!='\0')
{
len++;
i++;
}
for(i=len-1;i>=0;i--)
{
temp=(int)(tempbuf1[i]+tempbuf2[i]+jinwei-96);
if(temp>=10)
{
temp=temp-10;
jinwei=1;
}
else jinwei=0;
result[i]=(char)(temp+48);
}
ThrowAway_0 (result);
}
//================================================
void ThrowAway_0 (char *tempbuf ) // 去除结果前面的 连续的无意义的 "0"
{
char buf[200]={0};
int n = strlen(tempbuf)-1;
int i=0;
while(i=0;i--)
{
temp = (int)tempbuf1[i] - (int)tempbuf2[i] - jiewei;
if (temp>=0)
{
result[i]=(char)(temp+48);
jiewei=0;
}
else if (temp<0)
{
result[i]=(char)(temp+10+48);
jiewei=1;
}
}
ThrowAway_0 (result);
}
else if(ret==0)
{
memset(result,0,200);
result[0]='0';
}
else if(ret==-1)
{
for(i=len-1;i>=0;i--)
{
temp = (int)tempbuf2[i] - (int)tempbuf1[i] - jiewei;
if (temp>=0)
{
result[i]=(char)(temp+48);
jiewei=0;
}
else if (temp<0)
{
result[i]=(char)(temp+10+48);
jiewei=1;
}
}
ThrowAway_0 (result);
memset(buf1,0,200);
sprintf(buf1,"-%s",result);
strcpy(result,buf1);
}
}
//======================================================================
//===================================================================================
int Compare(char *tempbuf1,char *tempbuf2)
{
ThrowAway_0 (tempbuf1);
ThrowAway_0 (tempbuf2);
char buf1[200]={0};
char buf2[200]={0};
Trans(tempbuf1,tempbuf2,buf1,buf2);
memset(tempbuf1,0,200);
memset(tempbuf2,0,200);
strcpy(tempbuf1,buf1);
strcpy(tempbuf2,buf2);
int ret=1;
int count=0;
while(count<200)
{
int m=(int)tempbuf1[count]-48;
int n=(int)tempbuf2[count]-48;
if(m==n)
{
count++;
ret=0;
}
else if(m>n)
{
// printf("tempbuf1>tempbuf2\n");
ret=1;
break;
}
else if(m 2.头文件
#include
#include
#include
//extern "C" __declspec(dllexport)
void Add (char *tempbuf1, char *tempbuf2, char *result); // 大数相加 result = tempbuf1 + tempbuf2
//extern "C" __declspec(dllexport)
void Sub(char *tempbuf1, char *tempbuf2, char *result); // 大数相减 result = tempbuf1 - tempbuf2 (默认前者大)
int Compare(char *tempbuf1,char *tempbuf2);
//extern "C" __declspec(dllexport)
void Chen (char *tempbuf1, char *tempbuf2, char *result); // 大数相乘 result = tempbuf1 * tempbuf2
void Trans (char *str_num1, char *str_num2, char *tempbuf1, char *tempbuf2); // 大数转化为等长，且最前面添加 “0”
//extern "C" __declspec(dllexport) // 大数除法 div_result = tempbuf1 / tempbuf2
void Mod(char *tempbuf1, char *tempbuf2, char *result , char *div_result ); // 大数求余 result = tempbuf1 % tempbuf2
//extern "C" __declspec(dllexport)
void ChenFang (char *tempbuf1, int num, char *result); // 大数乘方 result = tempbuf1 ^ num
void ThrowAway_0 (char *tempbuf ); // 去除结果前面的 连续的无意义的 "0"