大数乘法、除法、加法、减法、以及求平方根源代码

//****** Big Number Sqrt ************************// #include<stdio.h> #include<stdlib.h> #include<string.h> #include<math.h> #define MAX 1000 /******************************************************************/ void reverse(char *from, char *to ) { int len=strlen(from); int i; for(i=0;i<len;i++) to[i]=from[len-i-1]; to[len]='\0'; } /****************************************************************/ int call_minus(char *large, char *small, char *result) { char L[MAX], S[MAX]; int l,s,now,hold,diff; l=strlen(large); s=strlen(small); if(l<s) return 0; if(l==s){ if(strcmp(large, small)<0) return 0; } reverse(large,L); reverse(small,S); for(;s<l;s++) S[s]='0'; S[s]='\0'; for(now=0,hold=0;now<l;now++){ diff=L[now]-(S[now]+hold); if(diff<0){ hold=1; result[now]=10+diff+'0'; } else{ result[now]=diff+'0'; hold=0; } } for(now=l-1;now>0;now--){ if(result[now]!='0') break; } result[now+1]='\0'; reverse(result,L); strcpy(result,L); return 1; } /******************************************************************/ void call_mult(char *first,char *sec,char *result) { char F[MAX],S[MAX],temp[MAX]; int f_len,s_len,f,s,r,t_len,hold,res; f_len=strlen(first); s_len=strlen(sec); reverse(first,F); reverse(sec,S); t_len=f_len+s_len; r=-1; for(f=0;f<=t_len;f++) temp[f]='0'; temp[f]='\0'; for(s=0;s<s_len;s++) { hold=0; for(f=0;f<f_len;f++) { res=(F[f]-'0')*(S[s]-'0') + hold+(temp[f+s]-'0'); temp[f+s]=res%10+'0'; hold=res/10; if(f+s>r) r=f+s; } while(hold!=0) { res=hold+temp[f+s]-'0'; hold=res/10; temp[f+s]=res%10+'0'; if(r<f+s) r=f+s; f++; } } for(;r>0 && temp[r]=='0';r--); temp[r+1]='\0'; reverse(temp,result); } /****************************************************************/ void call_sqrt(char *number,char *result,char *extra){ int num,start,e,mul,l,r=0,len; char left[MAX],after[MAX]; char who[5],temp[MAX],two[5]; len=strlen(number); if(len%2==0){ num=10*(number[0]-'0') + number[1]-'0'; start=2; } else{ num=number[0]-'0'; start=1; } mul=(int) sqrt(num); result[0]=mul+'0'; result[1]='\0'; if(num-mul*mul ==0) extra[0]='\0'; else sprintf(extra,"%d",num-mul*mul); for(;start<len;start+=2){ e=strlen(extra); extra[e]=number[start]; extra[e+1]=number[start+1]; extra[e+2]='\0'; two[0]='2'; two[1]='\0'; call_mult(result,two,left); l=strlen(left); for(mul=9;mul>=0;mul--){ who[0]=mul+'0'; who[1]='\0'; strcat(left,who); call_mult(left,who,after); if(call_minus(extra,after,temp)==1){ result[++r]=mul+'0'; result[r+1]='\0'; strcpy(extra,temp); break; } else left[l]='\0'; } } result[++r]='\0'; } /******************************************************************/ int main(){ char fir[MAX],ex[MAX],res[MAX]; while(scanf("%s",&fir)==1){ call_sqrt(fir,res,ex); int len=strlen(res); for(int i=0;i<len;i++) printf("%c",res[i]); printf("\n"); } return 0; }