//[SolutionMethod]
public PowerSumAnswer BruteForce(PowerSumSample sample)
{
Int32 N = sample.N;
Int32 X = sample.X;
Int32 result = 0;
//Int32 MaxAddendumCount = (Int32) Math.Ceiling ((Math.Sqrt(8 * X + 1) - 1) / 2);
List <Int32> Pows = new List <Int32>()
{
0, 1
};
Int32 SummPows = 1;
Int32 MaxAddendumCount = 2;
Int32 i = 2;
while (true)
{
Int32 pow = (Int32)Math.Pow(i, N);
SummPows += pow;
Pows.Add(pow);
if (pow >= X)
{
break;
}
if (SummPows <= X)
{
MaxAddendumCount++;
}
i++;
}
for (int j = 1; j <= MaxAddendumCount; j++)
{
result += CountAddendums(Pows, j, X, 1);
}
return(new PowerSumAnswer()
{
ps = result
});
}
public TAnswer DP(TSample Sample)
{
PowerSumSample sample = Sample as PowerSumSample;
Int32 N = sample.N;
Int32 X = sample.X;
Int32 result = 0;
List <Int32> Pows = new List <Int32>()
{
0, 1
};
Int32 SummPows = 1;
Int32 MaxAddendumCount = 2;
Int32 Counter = 2;
while (true)
{
Int32 pow = (Int32)Math.Pow(Counter, N);
if (pow == X)
{
result++;
}
SummPows += pow;
Pows.Add(pow);
if (pow >= X)
{
break;
}
if (SummPows <= X)
{
MaxAddendumCount++;
}
Counter++;
}
Int32[,] DP = new Int32[Pows.Count + 1, Pows[Pows.Count - 1] + 1];
/*
* for (int i = 0; i < Pows.Count; i++)
* {
* DP[1, Pows[i]] = 1;
* }
*/
DP[0, Pows[0]] = 1;
for (int i = 1; i < Pows.Count; i++)
{
for (int j = 0; j <= X; j++)
{
if (Pows[i] <= j)
{
DP[i, j] = DP[i - 1, j] + DP[i - 1, j - Pows[i]];
}
else
{
DP[i, j] = DP[i - 1, j];
}
}
}
result = DP[Pows.Count - 1, X];
return(new PowerSumAnswer()
{
ps = result
});
}