程序怎么不告诉我数字是升序还是降序？

Question

all the rest of the code works, but coming to the last point, that of the order of numbers, the code either tells me that it is in increasing form or it is neither. Could you help me understand why please?

#include <stdlib.h>
#include <stdio.h>

int main(){
int n;
int number;
int positive, negatives, null;
int even, odd;
int cont;
int rest;
int previous_number;
int increasing;
int decreasing;

increasing=1;
decreasing=1;
positive=0;
negative=0;
null=0;
even=0;
odd=0;

printf("insert a number\n");
scanf("%d",&n);

for(cont=1;cont<=n;cont++){
printf("insert a number\n");
scanf("%d",&number);

here the code works by checking if the number is positive, negative or null

if(number>0){
  positive++;
}else if(number<0){
  negatives++;
}else{
  null++;
}

here also seeing if it is even or odd rest=number%2;

if(rest==0){
  even=even+1;
}else{
  odd=odd+1;
}

and here the code doesn't work

if(number>previous_number){
  decreasing=0;
}else{
    if(number<previous_number){
  increasing=0;
}
  else{
    increasing=0;
    decreasing=0;
 }
 previous_number=number;
}

  

printf("the positive numbers are: %d \n",positive);
printf("the negative numbers are: %d \n",negative);
printf("the null numbers are: %d \n",null);
printf("the even numbers are: %d \n",even);
printf("the odd numbers are: %d \n",odd);
if (increasing==1){
  printf("the numbers are arranged in ascending order\n");
}else if(decrescente==1){
  printf("the numbers are arranged in descending order\n");
}else{
  printf("the numbers are arranged neither in increasing nor in decreasing order\n");
}
system("pause");
return 0;
}

Answer 1

You have a variable called "negative" and one called "negatives". I think this is the source of the issue. Also one called decreasing and another called decrescente which I think are supposed to be the same.

As a tip: a lot of the variables which are ints would be better as booleans. You are using the ++ operator to set a int to 1 by which you mean true which is unintuitive.

Answer 2

You don't have a value for previous_number in the first iteration. I suggest you to change this part:

 for(cont=1;cont<=n;cont++){
     printf("insert a number\n");
     scanf("%d",&number);
     ...
     previous_number=number;
 }

to this:

 scanf("%d",&number); //read a first time before the loop
 for(cont=2;cont<=n;cont++){ //start the loop one number further so it will read one less
     previous_number=number; //start by saving the old number then reading the new one after.
     
     //do the rest as you did before.
     printf("insert a number\n");
     scanf("%d",&number);
     ...
     
 }