Triplet problem : Solve it and remove the error - c

Question

#include<stdio.h>
#include<stdbool.h>
#include<malloc.h>
// function called
long long good_triplets (int* arr, int n) {
int count=0;
if(1<=n<=100000)
{
for(int i=0;i<=n;i++)
{
if((((arr[i]+arr[i+1]+arr[i+2])%arr[i ])==0) &&
(((arr[i]+arr[i+1]+arr[i+2])%arr[i+1])!=0) &&
(((arr[i]+arr[i+1]+arr[i+2])%arr[i+2])!=0) )
count=count + 6;
if((((arr[i]+arr[i+1]+arr[i+2])%arr[i+1])==0) &&
(((arr[i]+arr[i+1]+arr[i+2])%arr[i ])!=0) &&
(((arr[i]+arr[i+1]+arr[i+2])%arr[i+2])!=0) )
count=count + 6;
if((((arr[i]+arr[i+1]+arr[i+2])%arr[i+2])==0) &&
(((arr[i]+arr[i+1]+arr[i+2])%arr[i+1])!=0) &&
(((arr[i]+arr[i+1]+arr[i+2])%arr[i])!=0) )
count=count + 6;
}
}
return count;
}
//main funtion
int main() {
int n;
scanf("%d", &n);
int i_arr;
int *arr = (int *)malloc(n * sizeof(int));
for(i_arr=0; i_arr<n; i_arr++)
scanf("%d", &arr[i_arr]);
long long out_ = good_triplets(arr, n);
printf("%lld", out_);
}
'remove floating point exception'
'it is a hacker earth que'
'1.Remove floating point exception
2.help quickly please'
QUESTION: why am I getting the Floating Point Exception and how do I fix it?

Answer 1

if(1<=n<=100000) is wrong. It does not work this way in C. My proposition for that is to use logical and statement (&&) by writing:
if (1 <= n && n <= 100000)
You try to limit the loop to n in line: for(int i=0;i<=n;i++) but you should have < sign instead of <=. Try to use: for (int i=0; i<n; i++) to limit it to n.
Additionally, When you are limitting it to n then you should not use arr[i+1] or arr[i+2], because you are accessing values out of the array bounds (from memory which is just after the array). This is a reason of that exception. If you have some non-zero trash, then most probably your code will not have a floating point exception. Because you are using arr[i+1] and arr[i+2] in modulo operation and in some way they could be zero, then according to standard you can have the undefined behavior.
Try to use (according to your code; I do not know a purpose of it):
long long good_triplets(int *arr, int n) {
int count = 0;
if (3 <= n && n <= 100000) {
for (int i = 0; i < (n - 2); i++) {
if ((((arr[i] + arr[i + 1] + arr[i + 2]) % arr[i]) == 0) &&
(((arr[i] + arr[i + 1] + arr[i + 2]) % arr[i + 1]) != 0) &&
(((arr[i] + arr[i + 1] + arr[i + 2]) % arr[i + 2]) != 0))
count = count + 6;
if ((((arr[i] + arr[i + 1] + arr[i + 2]) % arr[i + 1]) == 0) &&
(((arr[i] + arr[i + 1] + arr[i + 2]) % arr[i]) != 0) &&
(((arr[i] + arr[i + 1] + arr[i + 2]) % arr[i + 2]) != 0))
count = count + 6;
if ((((arr[i] + arr[i + 1] + arr[i + 2]) % arr[i + 2]) == 0) &&
(((arr[i] + arr[i + 1] + arr[i + 2]) % arr[i + 1]) != 0) &&
(((arr[i] + arr[i + 1] + arr[i + 2]) % arr[i]) != 0))
count = count + 6;
}
}
return count;
}