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  1. #include <iostream>
  2. #include <cstring>
  3. using namespace std;
  4.  
  5. int a[1550];
  6.  
  7. #define LL long long int
  8. // returns the square sum of digits
  9. int sqSum(LL num){
  10. 	int ans=0;
  11.  
  12. 	while(num){
  13. 		ans=ans+(num%10)*(num%10);
  14. 		num/=10;
  15. 	}
  16.  
  17.     return ans;
  18.  
  19. }
  20.  
  21. void pre(){
  22. 	fill(a,a+1550,0);
  23.  
  24. 	int temp,last;
  25.  
  26. 	a[0]=0;a[1]=1;
  27.  
  28. 	for(int i=2;i<1550;i++){
  29. 		if(a[i]==0){// condition if the current value is not processed
  30. 			a[i]=-1;// let us assume -1 ->infinite loop and +1 for other case
  31.  
  32. 		//here i'm assuming that series is infinote 
  33. 			temp=sqSum(i);
  34. 			while(a[temp]==0){
  35. 				a[temp]=-1;
  36. 				temp=sqSum(temp);
  37. 			}
  38. 		// if series is not infinite then again calculate	
  39. 			if(a[temp]==1){
  40. 				a[i]=1;
  41.  
  42. 				temp=sqSum(i);
  43.  
  44. 				while(a[temp]!=1){
  45. 					a[temp]=1;
  46. 					temp=sqSum(temp);
  47. 				}
  48. 			}
  49. 		}		
  50. 	}
  51.  
  52.  
  53.  
  54. }
  55. int main() {
  56. 	pre();
  57.  
  58.     LL n,m;
  59.  
  60.     while(1){
  61.         scanf("%lld %lld",&n,&m);
  62.         if(!n&&!m)   break;
  63.  
  64.         LL count=0;
  65.  
  66.         for(LL i=n;i<=m;i++){
  67.             if(a[sqSum(i)]==-1)     count++;
  68.         }
  69.  
  70.         printf("%lld\n",count);
  71.  
  72.     }
  73. 	return 0;
  74. }
Success #stdin #stdout 0s 3476KB
comments (?)
stdin 
1 10
1 100
0 0
stdout 
7
80
https://ideone.com/8oQrcP
problem UNHAPPY, based on SPOJ submission 17790155 (C++14), 2016-09-26 18:22:01
language:
C++14 (gcc 8.3)
created:
8 years ago
visibility:
secret

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