基于的課件第八節(jié)

1、TSINGHUA UNIVERSITY函數(shù)指針的使用設(shè)計(jì)程序，隨機(jī)生成 8 個 1099 之間的整數(shù)，調(diào)用 stdlib 庫的 qsort 函數(shù)對其進(jìn)行排序qsort 函數(shù)原型void qsort( void * base, unsigned int number_of_elements, unsigned int size_of_elements, int ( * compare )( const void *, const void * ) ); 調(diào)用時需按照下述格式實(shí)現(xiàn)自己的比較函數(shù) int ( * compare )( const void *, const void * );比較函數(shù)

2、示例int MyCompareFunc( const void * e1, const void * e2 );比較函數(shù)必須返回正負(fù)值（一般為正負(fù) 1）或 0 ，規(guī)則按照題目要求自定義TSINGHUA UNIVERSITY函數(shù)指針的使用：main.cpp#include #include using namespace std;#include arrmanip.h#define NUMBER_OF_ELEMENTS 8int DoCompareObject( const void * e1, const void * e2 );TSINGHUA UNIVERSITY函數(shù)指針的使用：main.

3、cppint main() int aNUMBER_OF_ELEMENTS; GenerateIntegers( a, NUMBER_OF_ELEMENTS ); cout Array generated at random as follows: n; PrintIntegers( a, NUMBER_OF_ELEMENTS ); qsort( a, NUMBER_OF_ELEMENTS, sizeof(int), DoCompareObject ); cout After sorted: n; PrintIntegers( a, NUMBER_OF_ELEMENTS ); return 0

4、;int DoCompareObject( const void * e1, const void * e2 ) return CompareInteger( *(const int *)e1, *(const int *)e2 );TSINGHUA UNIVERSITY函數(shù)指針的使用：arrmanip.hvoid GenerateIntegers( int a, unsigned int n );int CompareInteger( int x, int y );void PrintIntegers( int a, unsigned int n );TSINGHUA UNIVERSITY函

5、數(shù)指針：arrmanip.cpp#include using namespace std;#include random.h#include arrmanip.hstatic const unsigned int lower_bound = 10;static const unsigned int upper_bound = 99;void GenerateIntegers( int a, unsigned int n ) unsigned int i; Randomize(); for( i = 0; i y ) return 1; else if( x = y ) return 0; el

6、se return -1;void PrintIntegers( int a, unsigned int n ) unsigned int i; for( i = 0; i n; i+ ) cout setw(3) ai; cout endl;TSINGHUA UNIVERSITY函數(shù)指針的使用函數(shù)指針的賦值同類型函數(shù)指針可以賦值，不同類型則不能賦值如何確定函數(shù)指針類型是否相同：函數(shù)參數(shù)與返回值不完全相同函數(shù)指針類型：用于區(qū)分不同類型的函數(shù)指針typedef int ( * COMPARE_OBJECT )( const void * e1, const void * e2 );前面添加 typedef 關(guān)鍵字，保證 COMPARE_OBJECT 為函數(shù)指針類型，而不是函數(shù)指針變量可以像普通類型一樣使用函數(shù)指針類型定義變量：COMPARE_OBJECT compare = DoCompareObject;qsort 函數(shù)的簡明書寫方法void qsort( v