大数相减模板

#include<cstdio>
#include<string.h>
#include<malloc.h>
#include<stdlib.h>
#define M 100000

void dele(char *a,char *b)//假设alen>beln
{
?if(a==NULL||b==NULL)
?? return ;
?int i,j,alen,blen;
?int lmax,lmin,p=0;
??? alen=strlen(a);
??? blen=strlen(b);
???
?? int *aa,*bb;?
??? aa=(int*)malloc(sizeof(int)*alen);
??? bb=(int*)malloc(sizeof(int)*alen);
??? for(i=0;i<alen;i++)
???? aa[i]=bb[i]=0;
?
??? for(i=alen-1,j=0;i>=0;i--,j++)
???? aa[j]=a[i]-'0';
??? for(i=blen-1,j++)
????? bb[j]=b[i]-'0';
??????
??
??? int *c;
??? c=(int*)malloc(sizeof(int)*alen);
??? for(i=0;i<alen;i++)
????? c[i]=0;
?????
??? for(i=0;i<alen;i++)//注释0，此种与下面注释1的相同
???? c[i]=aa[i]-bb[i];
?????
????? for(i=0;i<alen;i++)
????? {
????//c[i]+=aa[i]-bb[i];//注释1
????//{if(c[alen-1]<1)//这种格式与下面的这种注释2{}相对应,?同时与注释0的严格一致
???????? //alen-=1; }
????if(c[i]<0)
????? ?? {
????? ?? ?c[i]=c[i]+10;
????? ?? ?c[i+1]=c[i+1]-1;
????? ?? }
????? ?
????? }
???
???? for(i=alen-1;i>=0&&c[i]==0;i--)
?????? ;
?????? if(i>=0)
???????? for(;i>=0;i--)
?????? ?printf("%d",c[i]);
?????? ?else
?????? ?? printf("0");
?????? printf("n");
????? //{for(i=alen-1;i>=0;i--)//注释2
????? //printf("%d",c[i]);
???? // printf("n");}??
?????? ?
???? free(aa);
???? free(bb);
???? free(c);?????? ?
}

int main() { ?int T; ?scanf("%d",&T); ?while(T--) ?{ ??char *a,*b; ??? a=(char*)malloc(sizeof(char)*M); ??? b=(char*)malloc(sizeof(char)*M); ??? scanf("%s%s",a,b); ??? dele(a,b); ??? free(a); ??? free(b); ?} ?return 0; }