3n + 1 problem

Phewwww...At last i got my first correct submission at UVa online judge. Not anything spectacular. Its the same old 3n + 1 problem....Here is the perfect working code
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Question: 3n + 1 problem
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#include "iostream.h"

int cyclen[1000001];

int findCycleLength(int num) {
   int l = 0, index = num;
   long long n = num;
   if(cyclen[n] != 0) return cyclen[n];
   while(n != 1) {
       if(n <= 1000000) if(cyclen[n] != 0 ) return cyclen[index] = l + cyclen[n];
       if(n % 2 == 0) n/= 2;
       else n = 3 * n + 1;
       l++;
   }
   return cyclen[index] = l + 1;
}

int main()
{
   int i,j;

   while(true) {
       cin >> i >> j;
       if(cin.eof()) break;
       int min = (i < j)? i : j;
       int max = (i > j)? i : j;
       int maxlen = 0,len;
       for(int k = 0; k <= 1000000; k++) cyclen[k] = 0;
       for(int k = min; k <= max; k++) if((len = findCycleLength(k)) > maxlen) maxlen = len;
       cout << i << " " << j << " " << maxlen << endl;
   }
   return 0;
}

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