用C++实现大数的加减乘除.doc

1、大数的加法#include #include #include #include using namespace std;int main()map m;m0=0;m1=1;m2=2;m3=3;m4=4;m5=5;m6=6;m7=7;m8=8;m9=9;map mm;mm0=0;mm1=1;mm2=2;mm3=3;mm4=4;mm5=5;mm6=6;mm7=7;mm8=8;mm9=9;string sa,sb,st;int pa,pb,pc,t;int flag; while(cinsasb)flag=0;reverse(sa.begin(),sa.end();reverse(sb.begin(),sb.end();if(sa.size()sb.size()st=sa;sa=sb;sb=st;for(int j=0;j=sb.size() pb=0;else pb=msbj;pc=pa+pb+flag;if(pc=10)pc=pc-10;flag=1;elseflag=0;saj=mmpc;if(flag=1) sa+=1;reverse(sa.begin(),sa.end();coutsaendl;return 0;2、大数的减法#include #include #include #include using namespace std;int main()map m;m0=0;m1=1;m2=2;m3=3;m4=4;m5=5;m6=6;m7=7;m8=8;m9=9;map mm;mm0=0;mm1=1;mm2=2;mm3=3;mm4=4;mm5=5;mm6=6;mm7=7;mm8=8;mm9=9;string sa,sb,st;int pa,pb,pc,t;int flag;int kk;int n;while(cinn)for(int kk=0;kksasb;flag=0;reverse(sa.begin(),sa.end();reverse(sb.begin(),sb.end();for(int j=0;j=sb.size() pb=0;else pb=msbj;if(pa=pb)pc=pa-pb;flag=0;elsepc=pa+10-pb;flag=1;saj=mmpc;while(1)t=sa.length()-1;if(sat=0) sa.erase(t);else break;reverse(sa.begin(),sa.end();coutsaendl;return 0;3、大数的乘法#include #include using namespace std;unsigned int total400;unsigned int num1200;unsigned int num2200;int main() memset(total,0,sizeof(total); string str1,str2;int i; while(cinstr1str2) int len,index; len = str1.length(); index = 0; for (i=len-1;i=0;i-) num1index+ = str1i-0; len = str2.length(); index = 0; for (i=len-1;i=0;i-) num2index+ = str2i-0; for (i=0;istr1.length();i+) for (unsigned int j=0;jstr2.length();j+) totali+j += num1i*num2j; for (i=0;i=10) totali+1 += totali/10; totali %= 10; bool flag = false; for (i=399;i=0;i-) if (flag|totali) flag = true; couttotali; if (!flag) cout0; coutendl; return 0;4、大数的除法#include #include using namespace std;#define MAX 200int num1MAX+10;int num2MAX+10;unsigned int totalMAX+10;int Sub(int a,int b) if (b=a) if (a=b) return 0; else return -1; int i = 0; for (;ab;i+) b+; return i;int main() int n;int i; cinn; while(n-) memset(num1,0,sizeof(num1); memset(num2,0,sizeof(num2); memset(total,0,sizeof(total); string str1,str2; cinstr1str2; int len,index; len = str1.length(); index = 0; for (i=len-1;i=0;i-) num1index+ = str1i-0; len = str2.length(); index = 0; for (i=len-1;i=0;i-) num2index+ = str2i-0; if (str2.length()str1.length() cout0=0;i-) if (num1i) len1 = i+1; break; len = Sub(len1,len2); int index = 0; bool flag = false; for (i=len1-1;i=len;i-) if (num1inum2i-len) break; if (flag) len-; if (len=-1) break; while (+index) bool flag = false; for (i=len1-1;i=len;i-) if (num1inum2i-len) break; if (flag) index-; break; fo