BUILD-MAX-HEAP(A) P133

//@lx BUILD-MAX-HEAP p133

//time: 2010-9-8

#include "stdafx.h"

#include <iostream>

#include <vector>

using namespace std;

template <class T>

inline void PRINT_ELEMENTS(const T& col1, const char* optcstr = "")

{

typename T::const_iterator pos;

cout << optcstr;

for(pos = col1.begin(); pos != col1.end(); ++pos)

{

cout << *pos << ' ';

}

cout << endl;

}

int LEFT(int i)

{

return 2*i;

}

int RIGHT(int i)

{

return 2 * i + 1;

}

int PARENT(int i)

{

return i / 2;

}

void exchange(int& a, int& b)

{

int temp = 0;

temp = a;

a = b;

b = temp;

}

template <class T>

void MAX_HEAPIFY(vector<T>& A, int i)

{

int l = LEFT(i);

int r = RIGHT(i);

static int largest;

if(l <= A.size() && A[l-1] > A[i-1])

{

largest = l;

}

else

{

largest = i;

}

if(r <= A.size() && A[r-1] > A[largest-1])

{

largest = r;

}

if(largest != i)

{

exchange(A[i-1], A[largest-1]);

MAX_HEAPIFY(A, largest);

}

}

template <class T>

void BULD_MAX_HEAP(vector<T>& A)

{

int lenght = A.size();

for(int i = lenght / 2; i >= 1; i--)

{

cout << endl << i-1 << endl;

MAX_HEAPIFY(A, i);

PRINT_ELEMENTS(A);

}

}

int _tmain(int argc, _TCHAR* argv[])

{

vector<int> A;

A.push_back(4);

A.push_back(1);

A.push_back(3);

A.push_back(2);

A.push_back(16);

A.push_back(9);

A.push_back(10);

A.push_back(14);

A.push_back(8);

A.push_back(7);

cout << 5 << endl;

PRINT_ELEMENTS(A);

BULD_MAX_HEAP(A);

return 0;

}