BigInt_cpp.rar_BigInt.cpp

#include <iostream> #include <cstring> using namespace std; #define MAX 1000 //---------------------------------工具函数-------------------------------// void zhihuan(char *a, int l) { int i,len; len=l/2; char temp; for (i=0;i<len;i++) { temp=a[i]; a[i]=a[l-1-i]; a[l-1-i]=temp; } } void cleanzero(char *a) {//高位清零 int lena=strlen(a); int j=0; bool flag = false; for(j = 0; j < lena;j++) { if (a[j] == '0') { a[j]=0; flag =true; } else break; } if (flag) { for (int i= 0;i< lena-j;i++) { a[i]=a[i+j]; } a[lena-j]=0; } } void change(char *a,char *b) { int len_a=strlen(a); int len_b=strlen(b); char temp[MAX]; strcpy(temp,a); strcpy(a,b); strcpy(b,temp); int lab; lab=len_a; len_a=len_b; len_b=lab; } void leftshift(char*a, int n) //字符穿 左移 n { int len= strlen(a); for (int i =0;i < n;i++) { a[i+len]='0'; } a[i+len]=0; } int compare(char*a,char*b) {//a<b return 1 a>b return -1 a=b return 0 cleanzero(a); cleanzero(b); int lena=strlen(a); int lenb=strlen(b); lena=strlen(a); lenb=strlen(b); if (lena<lenb) { return 1; } else if (lena>lenb) { return -1; } else {//lena = lenb for (int i = 0;i < lena;i++) { if (a[i] < b[i]) { return 1; } else if (a[i] > b[i]) { return -1; } } return 0; } } //-----------------------------------ADD----------------------------------// void Add(char *a,char *b) { int i,j,len=0,flag=0;//len 和 的长度，flag进位； int la,lb; char temp[MAX]={0}; la=strlen(a); lb=strlen(b); for (i=la-1,j=lb-1;i>=0&&j>=0;i--,j--) { temp[len++]=(a[i]-'0'+b[j]-'0'+flag)%10+48; if (a[i]-48+b[j]-48+flag>9) { flag=1; } else { flag=0; } } while (i>=0) { temp[len++]=(a[i]+flag-48)%10+48; if(a[i]+flag-48>9) { flag=1; } else { flag=0; } i--; } while (j>=0) { temp[len++]=(b[j]+flag-48)%10+48; if(b[j]+flag-48>9) { flag=1; } else { flag=0; } j--; } if(flag==1) { temp[len++]='1'; } zhihuan(temp,len); strcpy(a,temp); return ; } //--------------------------------SUB---------------------------------------// void Sub(char *a,char *b) { if (compare(a,b) == 1) { a[0]='0'; a[1]=0; return ; } int len,i,j,c=0;//c jin wei int flag; int la,lb; cleanzero(a); cleanzero(b); la=strlen(a); lb=strlen(b); char temp[MAX]={0}; flag=compare(a,b); len=0; for(i=la-1,j=lb-1;j>=0;i--,j--) { if(a[i]+c<b[j]) { temp[len++]=(a[i]-48)+c+10-(b[j]-48)+48; c=-1; } else { temp[len++]=(a[i]-48)+c-(b[j]-48)+48; c=0; } } while(i>=0) { if(a[i]+c<'0') { temp[len++]=a[i]+c+10; c=-1; } else { temp[len++]=a[i]+c; c=0; } i--; } temp[len]='\0'; zhihuan(temp,len); strcpy(a,temp); } //--------------------------------MUL---------------------------------------// void Mul(char *a,char *b) { int i,j,da=0,db=0,ltp_a=0,ltp_b=0; int la=strlen(a); int lb=strlen(b); int c,tc; //jin wei char tp_a[MAX],tp_b[MAX]; int itp_b=0,itp_a=0; for(i=la-1;i>=0;i--) { itp_b=0; tc=c=0; for(j=lb-1;j>=0;j--) { tc=c; c=(c+(a[i]-'0')*(b[j]-'0'))/10; tp_b[itp_b++]=(tc+(a[i]-'0')*(b[j]-'0'))%10+'0'; } if(c>0) tp_b[itp_b++]=c+'0'; if(i!=la-1)//第一次循环不移位 { if(itp_a-(la-i-1)>itp_b) { for(j=itp_b;j<itp_a-(la-i-1);j++) tp_b[j]='0'; itp_b=itp_a-(la-i-1); } else { for(j=itp_a;j<itp_b+(la-i-1);j++) tp_a[j]='0'; itp_a=itp_b+(la-i-1); } c=0; for(j=0;j<itp_b;j++) { tc=c; c=(tc+tp_b[j]-'0'+tp_a[j+la-i-1]-'0')/10; tp_a[j+la-i-1]=(tc+tp_b[j]-'0'+tp_a[j+la-i-1]-'0')%10+'0'; } if(c>0) tp_a[itp_a++]=c%10+'0'; } else { for(j=0;j<itp_b;j++) tp_a[j]=tp_b[j]; itp_a=itp_b; } } while(tp_a[itp_a-1]=='0'&&itp_a>1) { tp_a[itp_a-1]='\0'; itp_a--; } zhihuan(tp_a,itp_a); tp_a[itp_a]='\0'; strcpy(a,tp_a); } //除法 void Div() { char b[MAX],a[MAX];//输入的大整数 //int la,lb;//数组长度 int num,div,len; cout<<"请输入两个数(只能为正数)：\n"; cout<<"被除数： "; cin>>b; cout<<"除数："; cin>>a; char x[MAX],y[MAX],z[MAX];//输入的大整数 x[0]='0'; x[1]=0; strcpy(y,b); //把b复值给y cleanzero(y); cleanzero(a); char tmp[]="1"; while (compare(y,a) != 1) { div = y[0]-'0'; num = a[0]-'0'; len = strlen(y)-strlen(a); if((div==num)&&(len==0)) { Add(x,tmp); Sub(y,a); cleanzero(y); break; } if((div<=num)&&len) { len--; div=(div*10)+y[1]-'0'; } div = div/(num + 1); z[0] = div+'0'; z[1]=0; if (len) { leftshift(z,len); } Add(x,z); char sss[MAX]; strcpy(sss,a); Mul(sss,z); Sub(y,sss); cleanzero(y); } cout<<"商为："<<x<<endl; cout<<"余数："<<y<<endl; } void main() { cout<<compare("10","11")<<endl; int flag=1; int chioce=0; char a[MAX]={0},b[MAX]={0}; while(flag==1) { cout<<"========================================================="<<endl; cout<<" ||**============欢迎使用大整数运算计算器============**||"<<endl; cout<<"========================================================="<<endl; cout<<" || 1.加法运算 o(∩_∩)o 2.减法运算 ||"<<endl; cout<<" || 3.乘法运算 o(∩_∩)o 4.除法运算 ||"<<endl; cout<<" || (*^__^*) 温馨提示：退出请按“0” (*^__^*) ||"<<endl; cout<<"========================================================="<<endl; cout<<"请选择:"; cin>>chioce; switch(chioce) { case 1: cout<<"请输入两个数(只能为正数)：\n"; cout<<"加数1:"; cin>>a; cout<<"加数2:"; cin>>b; Add(a,b); cout<<"两数之和为:"<<endl; cout<<a<<endl; break; case 2: cout<<"请输入两个数(只能为正数)：\n"; cout<<"被减数:"; cin>>a; cout<<" 减数:"; cin>>b; Sub(a,b); cout<<"两数之差为："<<endl; cout<<a<<endl; break; case 3: cout<<"请输入两个数(只能为正数)：\n"; cout<<"乘数1:"; cin>>a; cout<<"乘数2:"; cin>>b; Mul(a,b); cout<<"两数之积为："<<endl; cout<<a<<endl; break; case 4: Div(); break; case 0: flag=0; cout<<"--------------谢谢使用！--------------- "<<endl; break; default: cout<<"选择错误!请重新选择!"<<endl; } } }