编程练习：堆排序

/*=========================================================================#    FileName: heapSort.c# Description: 堆排序（数组实现）#  LastChange: 2012-06-03 15:03:00=========================================================================*/#include <stdio.h>#include <assert.h>void HeapAdjust( int r[],  int s, int m) {int j;int t = r[s];for( j = 2 * s; j <= m; j *= 2 ) {if( j < m && r[j] < r[j+1]) j++; /*j记录标号s的结点的子结点中最大的一个结点*/ if( t >= r[j] ) break; /*如果t比标号s的结点的最大子结点大，则标号s处即为值t的位置*/ r[s] = r[j];  /*否则标号s的结点的值改为标号j的结点的值*/ s = j; /*继续向下寻找放t的合适位置*/ }r[s] = t; /*找到了放t的位置，将此位置的结点的值改为t*/ }void _HeapSort( int r[] ,int length) {int i, tmp;/* 建立大顶堆，其中r[i]不小于r[2*i]和r[2*i+1] */for( i = length / 2; i > 0; --i )HeapAdjust(r, i, length);/* 将每次所得大顶堆的根与当前树最后一个结点交换， * 再将当前树长度减1，重新建立大顶堆，如此循环*/for( i = length; i > 1; --i) {tmp = r[i];r[i] = r[1];r[1] = tmp;HeapAdjust(r, 1, i-1);}}void HeapSort( int r[], int length) {if(r == NULL && length <= 0) return;/* 数组标号从0开始，但堆排序所用标号必须从1开始，故r在此处减1*/ _HeapSort( r-1, length); return;}void test1() {int r[1] = {21};HeapSort( r, sizeof(r) / sizeof(r[0]) );    assert(r[0] == 21);}void test2() {int r[10] = { 2,9,4,6,3,1,10,65,-1,0}; /*将数组看成按层顺序编好号的树*/ HeapSort( r, sizeof(r) / sizeof(r[0]) );    assert(r[0] == -1);assert(r[1] == 0);assert(r[2] == 1);assert(r[3] == 2);assert(r[4] == 3);assert(r[5] == 4);assert(r[6] == 6);assert(r[7] == 9);assert(r[8] == 10);assert(r[9] == 65);}int main( int argc, const char *argv[] ) {test1();test2();return 0;}