我的C程序中出现内存故障（coredump）错误消息？

Question

I am not able to understand why it is showing this error. I have never encountered such an error before. Here is my code, can you identify the mistake or the cause of it :

#include<stdio.h>
#include<math.h>

void dec2bin(int n,int bin[1000]){
int num = 0, index = 0, i;

while (n != 0){
bin[index] = n%2;
index++;
n = n/2;
  }

}

int Sub(int a[100],int b[1000],int ac[100],int siz){
 int i=siz-1,k=0;

for(;i>=0;i--){

if(b[i]){

  a[k++]=ac[siz-i-1];
  }
}
return k;
}

int sum(int a[100],int  s){

  int i,sum=0;

 for(i=0;i<s;i++)
   sum+=a[i];
  return sum;
 }

 main(){
  int b[1000],sub[100],a[100],n,i,s,count=0;

   printf("Enter n: ");
   scanf("%d",n);

   for(i=0;i<n;i++){

   printf("Enter number %d",i+1);
   scanf("%d",&a[i]);
 }

 printf("Enter S: ");
 scanf("%d",s);

 int no=(int)pow(2.0,(float)n);

 for (i=0;i<1000;i++)
   b[i]=0;

 for(i=0;i<no;i++){

   dec2bin(i,b);

  int siz=Sub(sub,b,a,n);

  if(sum(sub,siz)==s)
    count++;
}

printf("Subsets: %d",count);

}

And this code shows memory fault error immediately after entering the value of n .

Answer 1

You're using scanf slightly incorrectly.

The arguments following the format string need to be pointers to your objects, not the objects themselves.

scanf("%d", &n);

Do remember though, that scanf is very dangerous to use. Behavior is undefined for instance if the integer would overflow. Better to read a line safely then use strtol to parse it, since you can detect errors properly.

Answer 2

when taking input for n.

scanf("%d", &n);

You forgot a &