Compilare: user.c: In function ‘initialise_heap’: user.c:20:2: warning: implicit declaration of function ‘malloc’ [-Wimplicit-function-declaration] *root = (Node*)malloc(sizeof(Node)); ^ user.c:20:17: warning: incompatible implicit declaration of built-in function ‘malloc’ [enabled by default] *root = (Node*)malloc(sizeof(Node)); ^ user.c: In function ‘add_to_heap’: user.c:34:29: warning: incompatible implicit declaration of built-in function ‘malloc’ [enabled by default] Node *temp_node = (Node*)malloc(sizeof(Node)); ^ user.c:49:29: warning: incompatible implicit declaration of built-in function ‘malloc’ [enabled by default] Node *temp_node = (Node*)malloc(sizeof(Node)); ^ user.c: In function ‘process_data’: user.c:89:8: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d", &N); ^ user.c:91:8: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d", &el); ^ user.c:96:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d", &el); ^