#include <iostream>
using namespace std;
bool JudgeBSTSequence(int* BinSeq,int length)
{
int* root = NULL;
int* leftStart = NULL;
int* rightStart = NULL;
if ( BinSeq==NULL )
{
cout << "This is a NULL sequence.." << endl;
return false;
}
if ( length>0 )
{
root = BinSeq + length - 1;
}
else
{
return true;
}
leftStart = BinSeq;
while (leftStart < root && *leftStart < *root)
{
leftStart++;
}
rightStart = leftStart;
while (rightStart<root)
{
if ( *rightStart< *root)
{
cout << "This is not a Postorder of BST..." << endl;
return false;
}
rightStart++;
}
bool left = true, right = true;
left = JudgeBSTSequence(BinSeq, leftStart - BinSeq);
right = JudgeBSTSequence(leftStart, rightStart - leftStart);
return (left&right);
}
void Test(char* testName, int sequence[], int length, bool expected)
{
if (testName != NULL)
printf("%s begins: ", testName);
if (JudgeBSTSequence(sequence, length) == expected)
printf("passed.\n");
else
printf("failed.\n");
}
void Test1()
{
int data[] = { 4, 8, 6, 12, 16, 14, 10 };
Test("Test1", data, sizeof(data) / sizeof(int), true);
}
void Test2()
{
int data[] = { 4, 6, 7, 5 };
Test("Test2", data, sizeof(data) / sizeof(int), true);
}
void Test3()
{
int data[] = { 1, 2, 3, 4, 5 };
Test("Test3", data, sizeof(data) / sizeof(int), true);
}
void Test4()
{
int data[] = { 5, 4, 3, 2, 1 };
Test("Test4", data, sizeof(data) / sizeof(int), true);
}
void Test5()
{
int data[] = { 5 };
Test("Test5", data, sizeof(data) / sizeof(int), true);
}
void Test6()
{
int data[] = { 7, 4, 6, 5 };
Test("Test6", data, sizeof(data) / sizeof(int), false);
}
void Test7()
{
int data[] = { 4, 6, 12, 8, 16, 14, 10 };
Test("Test7", data, sizeof(data) / sizeof(int), false);
}
void Test8()
{
Test("Test8", NULL, 0, false);
}
int main(int argc, char* argv[])
{
Test1();
Test2();
Test3();
Test4();
Test5();
Test6();
Test7();
Test8();
return 0;
}