Programming and Graphics

4.10 Function templates 123

Bubble sort

The header filebsort.hcontaining the implementation of the bubble-sort
algorithm discussed in Section 3.8 reads:

#ifndef BSORTH

#define BSORTH

using namespace std;

template <class T>

T bsort (int n, T x[])

{

int Istop,k,i;

T save;

k = n-1; // number of comparisons

do{

Istop = 1; // will stop if Iflag 1

for (i=1;i<=k;i++) // compare

{

if(x[i]>x[i+1])

{save = x[i]; // swap

x[i]=x[i+1];

x[i+1] = save;

Istop = 0; // an exchange occurred; do not stop

}

}

k--; // reduce the number of comparisons

}while(Istop==0);

return x[n];

}

#endif

This function template returns to the calling program the entry at the bottom
of the sorted list. The function has two arguments: the integern, and the vector
variablex[]whose data type is left unspecified.

ReplacingTwith an actual data type, such asfloat, we obtain the
familiar function definition:

float bsort (int n, float x[])

The main programcities.cclisted below calls this template function to
alphabetize a list of cities:

#include <iostream>

#include <iomanip>