/in/foo.c: In function 'main':
/in/foo.c:9:25: warning: implicit declaration of function 'malloc' [-Wimplicit-function-declaration]
         nums[i] = (int*)malloc(sizeof(int)*2);
                         ^~~~~~
/in/foo.c:9:25: warning: incompatible implicit declaration of built-in function 'malloc'
/in/foo.c:9:25: note: include '<stdlib.h>' or provide a declaration of 'malloc'