tsaiwn@magpie qsort> cat -n myqsort.cpp
     1  //myqsort.cpp  -- demostration of quick sort, using template function
     2  //CopyLeft by tsaiwn@csie.nctu.edu.tw
     3  #include<iostream.h>
     4  template<class GG> void swap(GG& x, GG& y){ GG t=x; x=y; y=t; }
     5  template<class GG>
     6  void myqsort(GG x[], int left, int right) {
     7     int i=left, j=right, flag= -1;
     8     while(i < j) {
     9        if(x[i] > x[j]) {       /* 由小到大排 */
    10           swap(x[i], x[j]);
    11           //GG t = x[i]; x[i]=x[j]; x[j]=t;   /* 或是這樣也可以 */
    12           flag = - flag;
    13        }
    14        if(flag<0) --j;  else i++;
    15     }
    16     if(left+1 < i) myqsort(x, left, i-1);     /* 左邊多於 1 個 */
    17     if(i+1 < right) myqsort(x, i+1, right);   /* 右邊多於 1 個 */
    18  }
    19  long m[ ] = { 77, 85, 82, 55, 66, 96, 79, 73, 94 };
    20  int nofm = (sizeof(m) / sizeof(long) );
    21  double y[ ] = { 85.5, 94.5, 73.5, 77.5, 66.5, 82.5, 55.5, 96.5, 79.5, 99.5};
    22  int nofy = (sizeof(y) / sizeof(double) );
    23  template<class YY>
    24  void print(YY x[], int n) {
    25     cout << x[0];
    26     for(int i=1; i< n; ++i) {
    27        if(i%5 == 0 ) cout << endl;     /* 5 elements per line */
    28        else cout << ", ";
    29        cout << x[i];
    30     }
    31     cout << endl;
    32  }
    33  int main( ) {
    34     cout << "Before sort:\n"; print(m, nofm);
    35     myqsort(m, 0, nofm-1);
    36     cout << "After sort:\n";
    37     print(m, nofm);
    38     cout << "------" << endl;
    39     cout << "Before sort:\n"; print(y, nofy);
    40     myqsort(y, 0, nofy-1);
    41     cout << "After sort:\n";
    42     print(y, nofy);
    43  }
tsaiwn@magpie qsort> g++ myqsort.cpp
tsaiwn@magpie qsort> ./a.out
Before sort:
77, 85, 82, 55, 66
96, 79, 73, 94
After sort:
55, 66, 73, 77, 79
82, 85, 94, 96
------
Before sort:
85.5, 94.5, 73.5, 77.5, 66.5
82.5, 55.5, 96.5, 79.5, 99.5
After sort:
55.5, 66.5, 73.5, 77.5, 79.5
82.5, 85.5, 94.5, 96.5, 99.5
tsaiwn@magpie qsort> exit
exit

Script done on Mon Dec 24 21:58:52 2001