function CompareStringsInPercent(Str1, Str2:
string): Byte;
type
TLink =
array[0..1]
of Byte;
var
tmpPattern: TLink;
PatternA, PatternB:
array of TLink;
IndexA, IndexB, LengthStr: Integer;
begin
Result := 100;
// Building pattern tables
LengthStr := Max(Length(Str1), Length(Str2));
for IndexA := 1
to LengthStr
do
begin
if Length(Str1) >= IndexA
then
begin
SetLength(PatternA, (Length(PatternA) + 1));
PatternA[Length(PatternA) - 1][0] := Byte(Str1[IndexA]);
PatternA[Length(PatternA) - 1][1] := IndexA;
end;
if Length(Str2) >= IndexA
then
begin
SetLength(PatternB, (Length(PatternB) + 1));
PatternB[Length(PatternB) - 1][0] := Byte(Str2[IndexA]);
PatternB[Length(PatternB) - 1][1] := IndexA;
end;
end;
// Quick Sort of pattern tables
IndexA := 0;
IndexB := 0;
while ((IndexA < (Length(PatternA) - 1))
and (IndexB < (Length(PatternB) - 1)))
do
begin
if Length(PatternA) > IndexA
then
begin
if PatternA[IndexA][0] < PatternA[IndexA + 1][0]
then
begin
tmpPattern[0] := PatternA[IndexA][0];
tmpPattern[1] := PatternA[IndexA][1];
PatternA[IndexA][0] := PatternA[IndexA + 1][0];
PatternA[IndexA][1] := PatternA[IndexA + 1][1];
PatternA[IndexA + 1][0] := tmpPattern[0];
PatternA[IndexA + 1][1] := tmpPattern[1];
if IndexA > 0
then Dec(IndexA);
end
else
Inc(IndexA);
end;
if Length(PatternB) > IndexB
then
begin
if PatternB[IndexB][0] < PatternB[IndexB + 1][0]
then
begin
tmpPattern[0] := PatternB[IndexB][0];
tmpPattern[1] := PatternB[IndexB][1];
PatternB[IndexB][0] := PatternB[IndexB + 1][0];
PatternB[IndexB][1] := PatternB[IndexB + 1][1];
PatternB[IndexB + 1][0] := tmpPattern[0];
PatternB[IndexB + 1][1] := tmpPattern[1];
if IndexB > 0
then Dec(IndexB);
end
else
Inc(IndexB);
end;
end;
// Calculating simularity percentage
LengthStr := Min(Length(PatternA), Length(PatternB));
for IndexA := 0
to (LengthStr - 1)
do
begin
if PatternA[IndexA][0] = PatternB[IndexA][0]
then
begin
if Max(PatternA[IndexA][1], PatternB[IndexA][1]) - Min(PatternA[IndexA][1],
PatternB[IndexA][1]) > 0
then Dec(Result,
((100
div LengthStr)
div (Max(PatternA[IndexA][1], PatternB[IndexA][1]) -
Min(PatternA[IndexA][1], PatternB[IndexA][1]))))
else if Result < 100
then Inc(Result);
end
else
Dec(Result, (100
div LengthStr))
end;
SetLength(PatternA, 0);
SetLength(PatternB, 0);
end;