Add
void add(){
memset(a,0,sizeof a);
memset(b,0,sizeof b);
memset(c,0,sizeof c);
int lena=strlen(s1+1);
int lenb=strlen(s2+1);
for(int i=1;i<=lena;i++)a[i]=s1[lena-i+1]-'0';
for(int i=1;i<=lenb;i++)b[i]=s2[lenb-i+1]-'0';
lenc=max(lena,lenb);
for(int i=1;i<=lenc;i++){
c[i]=c[i]+a[i]+b[i];
c[i+1]+=c[i]/10;
c[i]%=10;
}
while(c[lenc+1]>0)lenc++;
}
Compare
int compare(char *s1,char *s2){
if(lena>lenb)return 1;
if(lena<lenb)return 0;
if(lena==lenb&&strcmp(s1,s2)==1)return 1;
return 0;
}
Sub
void sub(){
flag=0;
lena=strlen(s1+1);
lenb=strlen(s2+1);
lenc=max(lena,lenb);
if(compare(s1+1,s2+1)==0){
for(int i=1;i<=lenc;i++){
char c=s1[i];
s1[i]=s2[i];
s2[i]=c;
}
swap(lena,lenb);
flag=1;
}
for(int i=1;i<=lena;i++)a[i]=s1[lena-i+1]-'0';
for(int i=1;i<=lenb;i++)b[i]=s2[lenb-i+1]-'0';
for(int i=1;i<=lenc;i++){
c[i]=c[i]+a[i]-b[i];
if(c[i]<0){
c[i]+=10;c[i+1]-=1;}
}
while(c[lenc]==0&&lenc>1)lenc--;
if(flag==1&&c[lenc]!=0)printf("-");
}
Mul
void mul(){
lena=strlen(s1+1);
lenb=strlen(s2+1);
lenc=lena+lenb-1;
for(int i=1;i<=lena;i++)a[i]=s1[lena-i+1]-'0';
for(int i=1;i<=lenb;i++)b[i]=s2[lenb-i+1]-'0';
for(int i=1;i<=lena;i++){
for(int j=1;j<=lenb;j++){
c[i+j-1]+=a[i]*b[j];
c[i+j]+=c[i+j-1]/10;
c[i+j-1]%=10;
}
}
while(c[lenc+1]>0)lenc++;
while(c[lenc]==0&&lenc>1)lenc--;
}
大数除法和取余
const int maxn=1000+7;
char s1[maxn],s2[maxn];
int a[maxn],b[maxn],z[maxn];
int lena,lenb,lenbb,len;
int compare(){
if(lena>lenb)return 1;
if(lena<lenb)return -1;
if(lena==lenb){
for(int i=lena;i>0;i--){
if(a[i]>b[i])return 1;
if(a[i]<b[i])return -1;
}
}
return 0;
}
void sub(){
for(int i=1;i<=lena;i++){
a[i]=a[i]-b[i];
if(a[i]<0){
a[i]+=10;
a[i+1]--;
}
}
while(a[lena]==0&&lena>1)lena--;
}
int main(){
int T;
scanf("%d",&T);
while(T--){
int flag;
memset(a,0,sizeof a);
memset(b,0,sizeof b);
memset(z,0,sizeof z);
scanf("%s",s1+1);
scanf("%s",s2+1);
lena=strlen(s1+1);
lenb=strlen(s2+1);
len=lena-lenb;
lenbb=lenb;
for(int i=1;i<=lena;i++)a[i]=s1[lena-i+1]-'0';
for(int i=1;i<=lenb;i++)b[i]=s2[lenb-i+1]-'0';
if(compare()<0){
printf("%s\n",s1+1);
printf("0\n");
continue;
}
for(int i=lena;i>0;i--){
if(i>len)b[i]=b[i-len];
else b[i]=0;
}
lenb=lena;
for(int i=len+1;i>0;i--){
//除数最多有len+1位
while((flag=compare())>=0&&lenb>=lenbb){
sub();
z[i]++;
}
if(flag==-1){
for(int i=1;i<lenb;i++)b[i]=b[i+1];
b[lenb]=0;
lenb--;
}
}
for(int i=len+1;i>0;i--){
if(z[i]==0)len--;
else break;
}
for(int i=len+1;i>0;i--)
printf("%d",z[i]);
printf("\n");
for(int i=lena;i>0;i--)
printf("%d",a[i]);
printf("\n");
}
return 0;
}
最后记住随机应变