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@adevtus
Created March 12, 2012 09:29
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Lucky Numbers - C# - Interview Street
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
class ProgramBun
{
static int[] Primes = { 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89,
97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191,
193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293,
307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419,
421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 503, 509, 521, 523, 541,
547, 557, 563, 569, 571, 577, 587, 593, 599, 601, 607, 613, 617, 619, 631, 641, 643, 647, 653,
659, 661, 673, 677, 683, 691, 701, 709, 719, 727, 733, 739, 743, 751, 757, 761, 769, 773, 787, 797,
809, 811, 821, 823, 827, 829, 839, 853, 857, 859, 863, 877, 881, 883, 887, 907, 911, 919, 929, 937,
941, 947, 953, 967, 971, 977, 983, 991, 997, 1009, 1013, 1019, 1021, 1031, 1033, 1039, 1049, 1051, 1061,
1063, 1069, 1087, 1091, 1093, 1097, 1103, 1109, 1117, 1123, 1129, 1151, 1153, 1163, 1171, 1181, 1187, 1193,
1201, 1213, 1217, 1223, 1229, 1231, 1237, 1249, 1259, 1277, 1279, 1283, 1289, 1291, 1297, 1301, 1303, 1307,
1319, 1321, 1327, 1361, 1367, 1373, 1381, 1399, 1409, 1423, 1427, 1429, 1433, 1439, 1447, 1451, 1453, 1459, 1471,
1481, 1483, 1487, 1489, 1493, 1499, 1511, 1523, 1531, 1543, 1549, 1553, 1559, 1567, 1571, 1579, 1583, 1597, 1601,
1607, 1609, 1613, 1619, 1621, 1627, 1637, 1657, 1663, 1667, 1669, 1693, 1697, 1699, 1709, 1721, 1723, 1733, 1741,
1747, 1753, 1759, 1777, 1783, 1787, 1789, 1801, 1811, 1823, 1831, 1847, 1861, 1867, 1871, 1873, 1877, 1879, 1889, 1901,
1907, 1913, 1931, 1933, 1949, 1951, 1973, 1979, 1987, 1993, 1997, 1999};
public static void Main(String[] args)
{
int noTestCases;
string line = Console.ReadLine();
Int32.TryParse(line, out noTestCases);
//string line = "";
ulong[] minvalues = new ulong[noTestCases];
ulong[] maxvalues = new ulong[noTestCases];
int[] results = new int[noTestCases];
ulong maxMaxValue = 0;
for (int i = 0; i < noTestCases; i++)
{
line = Console.ReadLine();
string[] values = line.Split();
ulong.TryParse(values[0], out minvalues[i]);
ulong.TryParse(values[1], out maxvalues[i]);
if (maxvalues[i] > maxMaxValue) maxMaxValue = maxvalues[i];
}
//int maxPrime = (int)Math.Round((Math.Log10(maxMaxValue) + 1) * 81);
//bool[] Sieve = new bool[maxPrime];
//Sieve[0] = false;
//Sieve[1] = false;
//for (int i = 2; i < Sieve.Length; i++)
//{
// Sieve[i] = true;
//}
//for (int i = 2; i <= Sieve.Length / 2; i++)
//{
// if(Sieve[i] == true)
// for (int j = 2; (j * i) < Sieve.Length; j++)
// {
// Sieve[j * i] = false;
// }
//}
//for(int i = 0; i<Sieve.Length; i++)
// if(Sieve[i] == true)
// Console.Write(i + " ");
int count = 0;
while (count < noTestCases)
{
int luckyNumbers = 0;
int partSum = 0;
int partSumSq = 0;
while (minvalues[count] <= maxvalues[count])
{
if (minvalues[count] > 9 && (partSum == 0 || minvalues[count] % 10 == 0))
{//if there's no partial sum or we've reached another cycle
//Console.WriteLine("ding" + minvalues[count]);
partSum = 0;
partSumSq = 0;
ulong temp = minvalues[count];
temp /= 10;//last digit is ignored
while (temp != 0)//calculate partial sum of digits
{
byte digit = (byte)(temp % 10);
partSum += digit;
partSumSq += (int)(digit * digit);
temp /= 10;
}
}
//same for partial sum of squares
//partSum += (int)minvalues[count] % 10;
//partSumSq += (int)(minvalues[count] % 10) * (int)(minvalues[count] % 10);
int lastDigit = (int)minvalues[count] % 10;
if (Primes.Contains(partSum + lastDigit) &&
Primes.Contains(partSumSq + lastDigit * lastDigit))
{
luckyNumbers++;
}
minvalues[count]++;
}
results[count] = luckyNumbers;
count++;
}
for (int i = 0; i < results.Length; i++)
{
Console.WriteLine(results[i]);
}
}
}
@adevtus
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adevtus commented Mar 12, 2012

Code works but is a mess and poorly commented, sorry about that, will post a better version IF I can find a way to optimize it

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