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CodeFu 2010 Results

Final Round Results

sweko's solution for 300: NumberSequence, written in C#, submitted on 09.05.2010 12:32:48

using System;
using System.Collections.Generic;
using System.Text;

class NumberSequence
{
		public int findDigit (int N)
		{
			int currentLength = 0;
			int prevLength = 0;
			int index = 0;
			while (currentLength < N) {
				index ++;
				prevLength = currentLength;
				currentLength += length(index);
			}
			int offset =  N - prevLength;

			for (int i = 1; i <= index; i++) {
				int c = numCifri(i);
				offset -= c;
				if (offset <=0)
				{
					int seckati = i;
					//offset += c;
					for (int j = 0; j < -offset; j++) {
						seckati /=10;
					}
					seckati = seckati % 10;
					return seckati;
				}
			}
			return 1;
		}
		
		public int numCifri (int num)
		{
			int result = 0;
			while (num>0)
			{
				result ++;
				num /=10;
			}
			return result;
		}
		
		public int length(int num)
		{
			int result = 0;
			int size = 1;
			while (true) {
				if (num < TenN(size))
				{
					result += size * (num +1 - TenN(size-1));
					return result;
				}
				result += size * 9 * TenN(size -1);
				size ++;
			}
			
		}

		public int TenN (int exp)
		{
			int result = 1;
			for (int i = 0; i < exp; i++) {
				result *= 10;
			}
			return result;
		}
}