1 #include <stdio.h>
  2 #include <string.h>
  3 #define MAXN 1000
  4 struct BigNumber{
  5    int len;
  6    int v[MAXN];
  7 };
  8 bool isSmaller(BigNumber n1,BigNumber n2)
  9 {
 10  if(n1.len<n2.len)
 11   return 1;
 12  if(n1.len>n2.len)
 13   return 0;
 14  for(int i=n1.len-1;i>=0;i--)
 15  {
 16   if(n1.v[i]<n2.v[i])
 17    return 1;
 18   if(n1.v[i]>n2.v[i])
 19    return 0;
 20  }
 21  return 0;
 22 }
 23 BigNumber minus(BigNumber n1,BigNumber n2)
 24 {
 25  BigNumber ret;
 26  int borrow,i,temp;
 27  ret=n1;
 28  for(borrow=0,i=0;i<n2.len;i++)
 29  {
 30   temp=ret.v[i]-borrow-n2.v[i];
 31   if(temp>=0)
 32   {
 33    borrow=0;
 34    ret.v[i]=temp;
 35   }
 36   else
 37   {
 38    borrow=1;
 39    ret.v[i]=temp+2;
 40   }
 41  }
 42  for(;i<n1.len;i++)
 43  {
 44   temp=ret.v[i]-borrow;
 45   if(temp>=0)
 46   {
 47    borrow=0;
 48    ret.v[i]=temp;
 49   }
 50   else
 51   {
 52    borrow=1;
 53    ret.v[i]=temp+2;
 54   }
 55  }
 56  while(ret.len>=1 && !ret.v[ret.len-1])
 57   ret.len--;
 58  return ret;
 59 }
 60 BigNumber div2(BigNumber n)
 61 {
 62  BigNumber ret;
 63  ret.len=n.len-1;
 64  for(int i=0;i<ret.len;i++)
 65   ret.v[i]=n.v[i+1];
 66  return ret;
 67 }
 68 void gcd(BigNumber n1,BigNumber n2)
 69 {
 70  long b=0,i;
 71  while(n1.len && n2.len)
 72  {
 73   if(n1.v[0])
 74   {
 75    if(n2.v[0])
 76    {
 77     if(isSmaller(n1,n2))
 78      n2=minus(n2,n1);
 79     else
 80      n1=minus(n1,n2);
 81    }
 82    else
 83     n2=div2(n2);
 84   }
 85   else
 86   {
 87    if(n2.v[0])
 88     n1=div2(n1);
 89    else
 90    {
 91     n1=div2(n1);
 92     n2=div2(n2);
 93     b++;
 94    }
 95   }
 96  }
 97  if(n2.len)
 98   for(i=n2.len-1;i>=0;i--)
 99    printf("%d",n2.v[i]);
100  else
101   for(i=n1.len-1;i>=0;i--)
102    printf("%d",n1.v[i]);
103  while(b--)
104   printf("0");
105  printf("\n");
106 }
107 int main()
108 {
109  int cases,le,i;
110  BigNumber n1,n2;
111  char str1[MAXN],str2[MAXN];
112  scanf("%d",&cases);
113  for(int w=1;w<=cases;w++)
114  {
115   scanf("%s%s",str1,str2);
116   le=strlen(str1);
117   n1.len=le;
118   for(i=0;i<le;i++)
119    n1.v[i]=str1[le-1-i]-‘0‘;
120   le=strlen(str2);
121   n2.len=le;
122   for(i=0;i<le;i++)
123    n2.v[i]=str2[le-1-i]-‘0‘;
124    printf("Case #%d: ",w);
125   gcd(n1,n2);
126  }
127  return 0;
128 }