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CodeFu 2010 Results

Final Round Results

mangelovski's solution for 300: NumberSequence, written in Java, submitted on 09.05.2010 14:03:02

public class NumberSequence {
	
	  public int findDigit(int N) {
		  
		  if (N==1) return 1;
		  if (N==2) return 1;
		  if (N==3) return 2;
		  if (N==4) return 1;
		  if (N==5) return 2;
		  if (N==6) return 3;
		  if (N==7) return 1;
		  
		  int next=3;
		  int prev=2;
		  int stack=4;
		  int prevstack=-1;
		  while(stack<N){			  
			  if(next<10){
				  prev=next;
				  next++;
				  prevstack=stack;
				  stack+=prev;
				  
			  }
			  else{
				  if(next<100){
					  prev=next;
					 next++;
					  prevstack=stack;
					  stack+=9+2*(prev-9);
					  
				  }else{
					  if(next<1000)	{					  
					  prev=next;
					  next++;
					  prevstack=stack;
					  stack+=9+2*(90)+3*(prev-99);
					  }
					  else{
						 if(next<1000){
							 prev=next;
							 next++;
							  prevstack=stack;
							 stack+=9+2*(90)+3*(900)+4*(prev-999); 
					  }
					  }
				  }
				  
			  }
			  
		  }
		  if(stack==N) return 1;
		  N-=prevstack;
		  if(N<9) return N+1;
		  int tm=10;
		//  System.out.println(prev);
		//  System.out.println(prevstack);
		//  System.out.println(N);
		for(int i=9;i<=N;i++){
			int sec=tm;
			int size=Integer.toString(sec).length();
			int tn=(int) (sec/Math.pow(10, size-1));
		
			sec=(int) (sec%Math.pow(10, size-1));
			 if(i==N) return tn;
			while(sec>0){							
				  			  
				  size=Integer.toString(sec).length();
				  tn=(int) (sec%Math.pow(10, size-1));
				  sec=(int) (sec/Math.pow(10, size-1));
				  i++;						
			}
			tm++;
			if(i==N) return 0;
		}



	  return -1;
	  }
	  

}