Question

here is code from programming pearls this code prints random numbers in decreasing form

void randselect(m,n){
pre 0<=m<=n;
poset : m  distinct integers  from 0 ...n-1  printed in decreasing form
 if (m>0) 
 if ( bigrand() %n)<m
 print n-1//here i dont understand print  n-1 what means?printf(n-1) or?i will show code
 randselect(m-1.n-1);
else
 randselect(m,n-1)

there is another question :
how print it increasing order? here is code which has bugs

#include <iostream>
#include <stdlib.h>
#include <stdio.h>
using std::cout;
using std::printf;
using namespace std;

int bigrand(){  return RAND_MAX*rand()+rand();}

void randselect(int n,int m)
{
  if (m>0)
     if (bigrand()%n<m)
     {
         printf("",n-1);
         randselect(m-1,n-1);
     }
     else{
         randselect(m,n-1);
     }
}
int main()
{
  int m,n;

  cin>>n>>m;
  randselect(n,m);

  return 0;
}

please help it does not show me any output according to main code what is mistake in my code?

Answer 1

Your output problem is printf("",n-1);, which doesn’t have a format specifier and therefore doesn’t do anything with the remaining function values.

Change it to something like printf("%d\n", n - 1);, which will print out one integer (%d) per line (\n).