/in/foo.c: In function 'main':
/in/foo.c:5:10: warning: implicit declaration of function 'malloc' [-Wimplicit-function-declaration]
  int *a1=malloc(sizeof(int)*10000);
          ^~~~~~
/in/foo.c:5:10: warning: incompatible implicit declaration of built-in function 'malloc'
/in/foo.c:5:10: note: include '<stdlib.h>' or provide a declaration of 'malloc'