online c compiler

1Step 1) Go to http://www.codeblocks.org/downloads and click Binary Release.
2Step 2) Choose the installer with GCC Compiler, e.g., codeblocks-17.12mingw-setup.exe
3which includes MinGW's GNU GCC compiler and GNU GDB debugger with Code::Blocks source files.
4Step 3) Run the downloaded installer and accept the default options.
5Step 4) Accept the Agreement
6Step 5) Keep the component selection default and click Next.
7Step 6) You may change the installation folder and click Next.
8Step 7) To launch Code::Blocks double click on the icon.
9Step 8) It will detect the gcc compiler automatically, set it as default.
10Step 9) You will see the IDE Home screen.

1I Personally Like 
2https://www.programiz.com/c-programming/online-compiler/

1You can try https://www.onlinegdb.com/ this as well, works really well for me.
2You can also save code there.

1replit.com is your best shot tbh

1#include<stdio.h>
2void accept_num(int arr[],int n);
3int main(void)
4{
5    int n,ptu[n];
6    printf("Enter limit of element in an array:");
7    scanf("%d",&n);
8    accept_num(ptu,n);
9    
10   return 0; 
11}
12void accept_num(int arr[],int n)
13{
14    int i;
15    printf("\nEnter the element:");
16    for (i=0;i<n;i++)
17    {
18        scanf("%d",&arr[i]);
19    }
20    for (i=0;i<n;i++)
21    {
22        printf("\n arr[%d]=%d &arr[%d]=%u",i,arr[i],i,&arr[i]);
23    }
24}

1What is a compiler(C)?