Compilare: user.c: In function ‘main’: user.c:23:5: warning: implicit declaration of function ‘quick’ [-Wimplicit-function-declaration] quick(p,0,k); ^ user.c: At top level: user.c:55:6: warning: conflicting types for ‘quick’ [enabled by default] void quick(long long p[],int jos,int sus){ ^ user.c:23:5: note: previous implicit declaration of ‘quick’ was here quick(p,0,k); ^ user.c: In function ‘main’: user.c:10:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &n); ^ user.c:13:28: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] for(i=0;i<n;i++) fscanf(in, "%d %d", &x[i], &y[i]); ^