我的程序无限循环，我老实说不清楚为什么

Question

So the problem here was to write a program that uses pointers to point to functions and write it in such a way that it collects 10 doubles, gives feedback to the user of the program, sorts them and print the sorted results as proof. The problem is, the program either prints the printf statement in the beginning infinitely, or collects numbers infinitely.

Here is some code

#include <stdio.h>


void func1(double x);
void below_five(void);
void above_five(void);
void other(void);
void sort(double *p[], int n);
void print_doubles(double *p[], int n);

int main(void){

  double *numbers[9];
  int nbr;
  printf("\nEnter 10 doubles that are less than 5 or greater than 5, type 0 to exit");
  for(int i = 0; i < 10 ; i++)
  {

      scanf("%d", &nbr);
      func1(nbr);
      numbers[i] = nbr;

      if(nbr == 0)
        break;


  }
  sort(numbers, 10);
  print_doubles(numbers, 10);
  return 0;
}

void func1(double val)
{
  double (*ptr)(void);

  if(val <= 5.00){
    ptr = below_five;
  }else if((val > 5.00) && (val <= 10.00)){
    ptr = above_five;
  }else
    ptr = other;
}

void below_five(void){
  puts("You entered a number below or equal to five");
}

void above_five(void){
  puts("You entered a number above five");
}

void other(void){
  puts("You entered a number well above five.");
}

void sort(double *p[], int n)
{
double *tmp;
for(int i = 0; i < n; i++)
{
  if(p[i] > p[i+1]){
  tmp = p[i];
  p[i] = p[i+1];
  p[i + 1] = tmp;
}
}
}

void print_doubles(double *p[], int n)
{
  int count;
  for(count = 0; count < n; count++)
    printf("%d\n", p[count]);

}

Like I said, what I expect it to be able to do is collect doubles into the scanf method and then print the numbers after sorting them, but it seems the for loop collects doubles forever without end in this case.

What have I done wrong, exactly?

Answer 1

See my comments in your updated code. _{There are other modifications required, but the minimum updates needed to work your code is below}

#include <stdio.h>


void func1(double x);
void below_five(void);
void above_five(void);
void other(void);
    void sort(double p[], int n);  /* Simply use a array notation, 
arrays passed to functions decays to pointer */
    void print_doubles(double p[], int n); /* Simply use a array notation,
 arrays passed to functions decays to pointer */

int main(void){

  double numbers[10];
  double nbr; // Change type to double, as you're reading doubles
  printf("\nEnter 10 doubles that are less than 
           5 or greater than 5, type 0 to exit\n");
  for(int i = 0; i < 10 ; i++)
  {

      scanf("%lf", &nbr); // Use correct format specifier to read doubles
      func1(nbr);
      numbers[i] = nbr;

      if(nbr == 0)
        break;


  }
  sort(numbers, 10);
  print_doubles(numbers, 10);
  return 0;
}

void func1(double val)
{
  double (*ptr)(void);

  if(val <= 5.00){
    ptr = below_five;
  }else if((val > 5.00) && (val <= 10.00)){
    ptr = above_five;
  }else
    ptr = other;
  /* Why you set the pointer to function if you don't call it, 
     so call it here*/    
        (*ptr)();  
    }

void below_five(void){
  puts("You entered a number below or equal to five");
}

void above_five(void){
  puts("You entered a number above five");
}

void other(void){
  puts("You entered a number well above five.");
}

void sort(double p[], int n)  /* Your sorting routine is wrong ,
   see the modified code */
{
double tmp;
    for(int j = 0; j < n-1; j++)
    for(int i = 0; i < n-j-1; i++)
{
  if(p[i] > p[i+1]){
  tmp = p[i];
  p[i] = p[i+1];
  p[i + 1] = tmp;
}
}
}

void print_doubles(double p[], int n)
{
  int count;
  for(count = 0; count < n; count++)
    printf("%lf\n", p[count]); // Use correct format specifier

}

Demo Here