Compilare: user.c: In function ‘init’: user.c:35:2: warning: implicit declaration of function ‘malloc’ [-Wimplicit-function-declaration] a = (long long*)malloc((s + 1) * sizeof(long long)); ^ user.c:35:18: warning: incompatible implicit declaration of built-in function ‘malloc’ [enabled by default] a = (long long*)malloc((s + 1) * sizeof(long long)); ^ user.c: In function ‘main’: user.c:70:2: warning: implicit declaration of function ‘free’ [-Wimplicit-function-declaration] free(a); ^ user.c:70:2: warning: incompatible implicit declaration of built-in function ‘free’ [enabled by default] user.c:51:8: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(pf,"%d", &x); ^