交换

#include <iostream>using namespace std;template <typename T>void swap(T a[],int first,int second){T temp;temp = a[first];a[first] = a[second];a[second] = temp;}template <typename T>void reverse(T a[],int begin,int end){while(begin < end){swap(a,begin++,end--);}}template <typename T>void exchange(T a[],int begin,int mid,int end){reverse(a,begin,mid);reverse(a,mid+1,end);reverse(a,begin,end);}int main() {int a[] = {2,3,1,55,6,4,7,3};int len = sizeof(a)/sizeof(int);int mid = 3;    exchange(a, 0, mid ,len-1);//交换0~mid 与mid+1～len-1的数据    int i;    for (i = 0; i < len; ++i)        cout << a[i] << " ";    cout << endl;}