多功能冒泡排序 函數指標

#include <iostream>#include <iomanip>#include <cstdlib>using namespace std;void bubbleSort(int [],const int, bool(*)(int,int));void swap(int * const,int * const);bool ascending(int ,int);bool descending(int,int);void print_arr(int [],int);int main(){    int arr[]={3,42,1,100,689,2,24,45,36,47};    int len=sizeof(arr)/sizeof(*arr);    int flag=0;    cout << "原數組為:" << endl;    print_arr(arr,len);    cout<<"請選擇排序方法,升序(1),降序(2):";    cin>>flag;    if(flag==1){       bubbleSort(arr,len,ascending);    }    else if(flag==2){       bubbleSort(arr,len,descending);    }    else cout<<"輸入有誤!"<<endl;    print_arr(arr,len);    cout<<"done"<<endl;    system("pause");    return 0;}void bubbleSort(int arr[],const int len, bool(*sort_fun)(int,int)){    for(int i=0;i<len-1;++i){        for(int j=0;j<len-1-i;++j){            if(sort_fun(arr[j],arr[j+1]))                swap(arr[j],arr[j+1]);        }    }}bool ascending(int a,int b){    return a>b;}bool descending(int a,int b){    return a<b;}void swap(int * const a,int * const b){    int t=*a;    *a=*b;    *b=t;}void print_arr(int arr[],int len ){    for(int i=0;i<len;++i){        cout<<setw(5)<<right<<arr[i];    }    cout<<endl;}