Compilare: user.c: In function ‘main’: user.c:18:9: warning: implicit declaration of function ‘memset’ [-Wimplicit-function-declaration] memset(frecv, 0, MAX2); ^~~~~~ user.c:18:9: warning: incompatible implicit declaration of built-in function ‘memset’ user.c:18:9: note: include ‘<string.h>’ or provide a declaration of ‘memset’ user.c:46:5: warning: incompatible implicit declaration of built-in function ‘memset’ memset(frecv, 0, MAX2); ^~~~~~ user.c:46:5: note: include ‘<string.h>’ or provide a declaration of ‘memset’ user.c:51:13: warning: variable ‘ok’ set but not used [-Wunused-but-set-variable] int ok; ^~ user.c:10:5: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &p); ^~~~~~~~~~~~~~~~~~~ user.c:11:5: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d %d", &n, &k); ^~~~~~~~~~~~~~~~~~~~~~~~~~ user.c:14:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &v[i]); ^~~~~~~~~~~~~~~~~~~~~~