// The array size is limited to 200k elements, but that could be
// 200k * (200k - 1) / 2 inversions, so we need to use long when counting.
public static long Solve(int[] array)
{
var inversionBST = new InversionBST(array[0]);
long inversionCount = 0;
for (int i = 1; i < array.Length; ++i)
{
inversionCount += inversionBST.Add(array[i]);
}
return inversionCount;
}
// The array size is limited to 200k elements, but that could be
// 200k * (200k - 1) / 2 inversions, so we need to use long when counting.
public static long Solve(int[] array)
{
var inversionBST = new InversionBST(array[0]);
long inversionCount = 0;
for (int i = 1; i < array.Length; ++i)
{
inversionCount += inversionBST.Add(array[i]);
}
return(inversionCount);
}
// We can map Yoda's words to numbers using the ordered statement. Once
// we do that we need to count the number of inversions in the resulting
// array, just like CODESPTB or INVCNT.
public static int Solve(int wordCount, string[] yodaStatement, string[] orderedStatement)
{
var wordsOrderedIndices = new Dictionary <string, int>(wordCount);
for (int w = 0; w < wordCount; ++w)
{
wordsOrderedIndices[orderedStatement[w]] = w;
}
int[] yodaStatementWordIndices = yodaStatement
.Select(w => wordsOrderedIndices[w])
.ToArray();
var inversionBST = new InversionBST(yodaStatementWordIndices[0]);
int inversionCount = 0;
for (int i = 1; i < wordCount; ++i)
{
inversionCount += inversionBST.Add(yodaStatementWordIndices[i]);
}
return(inversionCount);
}
