大整数四则运算_C语言课程设计
* 大整数的四则运算。
* 1 大整数指超过十位的十进制整数，这里为简便，假定不超过五十位。
* 2 用数组来表示大整数，在此基础上编写出实现大整数加、减、乘、除
* 的程序，并努力加以优化。
*/
#include<stdio.h>
#include<math.h>
#include<string.h>
#include<stdlib.h>
#define MAX 50
/*
* 处理大数的加法论文网http://www.lwfree.com/
*/
void getsum(char bigIntFir[MAX],charbigIntSec[MAX]){
int i,j,k,m,mid;
char ch[MAX];
for(i=0;bigIntFir!=NULL;i++);
for(j=0;bigIntSec[j]!=NULL;j++);
for(k=0;k<MAX;k++)
ch[k]='0';
i--;
j--;
m=0;
while(i>=0&&j>=0){
mid=(bigIntFir-'0')+(bigIntSec[j]-'0');
if((mid+(ch-'0'))>=10)
{
ch=((ch-'0')+mid-10)+'0';
ch[m+1]=((ch[m+1]-'0')+1)+'0';
m++;
}
else{
ch=(ch-'0')+mid+'0';
m++;
}
i--;
j--;
}
while(i>=0){
ch=(ch-'0')+(bigIntFir-'0')+'0';
i--;
m++;
}
while(j>=0){
ch=(ch-'0')+(bigIntSec[j]-'0')+'0';
j--;
m++;
}
if(ch=='0')
m--;
printf("result is: ");
while(m>=0){
printf("%c",ch);
m--;
}
}
/*
* 处理数组的减法
*/
void getminus(charbigIntFir[MAX],char bigIntSec[MAX]){
int i,j,k,m,mid;
char ch[MAX];
for(i=0;bigIntFir!=NULL;i++);
for(j=0;bigIntSec[j]!=NULL;j++);
for(k=0;k<MAX;k++)
ch[k]='0';
i--;
j--;
m=0;
if(i>=j||(bigIntFir-bigIntSec[j])>=0){
while(i>=0&&j>=0){
mid=(bigIntFir-'0')-(bigIntSec[j]-'0');
if(ch!='-'&&(mid+(ch-'0'))<0){
ch[m+1]='-';
ch=((ch-'0')+mid+10)+'0';
m++;
} else if (ch!='-'&&(mid+(ch-'0'))>=0)
{
ch=(ch-'0')+mid+'0';
m++;
}else if(ch=='-'){
ch=(mid-1)+'0';
}
i--;
j--;
}
while(i>=0){
if(ch=='-'){
ch=((bigIntFir-'0')-1)+'0';
}else {
ch=bigIntFir;
}
i--;
m++;
}
while(j>=0){
if(ch=='-'){
ch=((bigIntSec[j]-'0')-1)+'0';
}else
ch=bigIntSec[j];
j--;
m++;
}
if(ch=='0')
m--;
printf("resultis: ");
while(m>=0&&ch!='-'){
printf("%c",ch);
m--;
}
}else{
printf("ERROR!");
}
}
/*
*处理数组的乘法
*注：只能执行多为乘以个位数
*/
void getmultiply(charbigIntFir[MAX],char bigIntSec[MAX]){
int i,j,k,m,mid;
char ch[MAX];
for(i=0;bigIntFir!=NULL;i++);
for(j=0;bigIntSec[j]!=NULL;j++);
for(k=0;k<MAX;k++)
ch[k]='0';
i--;
j--;
m=0;
if(j==0){
while(i>=0){
mid=(bigIntFir-'0')*(bigIntSec[j]-'0');
if((mid+(ch-'0'))>=10){
ch=((ch-'0')+mid%10)+'0';
ch[m+1]=((ch[m+1]-'0')+mid/10)+'0';
m++;
}else{
ch=(ch-'0')+mid+'0';
m++;
}
i--;
}
printf("result is: ");
if(ch=='0')
m--;
while(m>=0){
printf("%c",ch);
m--;
}
}else{
printf("\nSorry! input ERROR!\n");
}
}
/*
* 处理数组的除法
* 注：只能处理多位数除以一位数
*/
void getdiv(char bigIntFir[MAX],charbigIntSec[MAX]){
int i,j,k,m,mid;
char ch[MAX];
int temp1=0,temp2=0;
for(i=0;bigIntFir!=NULL;i++);
i--;
for(j=0;bigIntSec[j]!=NULL;j++);
j--;
printf("the result is:");
if(i<9){
for(k=0;k<=i;k++){
temp1=(bigIntFir[k]-'0')+temp1*10;
}
for(k=0;k<=j;k++){
temp2=(bigIntSec[k]-'0')+temp2*10;
}
printf("%.2f\n",temp1/(float)temp2);/**/
}else{
for(k=0;k<8;k++){
temp1=(bigIntFir[k]-'0')+temp1*10;
}
printf("%d",temp1/(bigIntSec[0]-'0'));
temp1=temp1%(bigIntSec[0]-'0');
for(k=8;k<=i;k++){
temp1=(bigIntFir[k]-'0')+temp1*10;
}
printf("%d",temp1/(bigIntSec[0]-'0'));
}
}
void Control(char bigIntFir[MAX],char bigIntSec[MAX]){
char ch;
printf("\na :plus (+)\nb:sub (-)\nc :mul (*)\nd :divi (/)\n");
printf("Now,scanf yourchance according to the view: ");
scanf("%s",&ch);
switch(ch){
case 'a': printf("\nYou choose plus...\n");
getsum(bigIntFir,bigIntSec);
break;
case 'b': printf("\nYou choose sub ...\n");
getminus(bigIntFir,bigIntSec);
break;
case 'c': printf("\nYou choose mul...\n");
getmultiply(bigIntFir,bigIntSec);
break;
case 'd': printf("\nYou choose div...\n");
getdiv(bigIntFir,bigIntSec);
break;
defalut: printf("\nThe input you set is wrong,Ican do nothing!\n");
break;
}
}
void main(){
charbigIntFir[MAX],bigIntSec[MAX],ch;
int i,j,m,n;
printf("Input the firstInteger : ");
scanf("%s",bigIntFir);
printf("Input the secondInteger: ");
scanf("%s",bigIntSec);
printf("\n");
Control (bigIntFir,bigIntSec);
exit(0);
}