Compilare: main.c: In function 'main': main.c:38:2: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d", &n, &k); ^~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:41:3: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d", &a, &b); ^~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from /usr/include/string.h:635:0, from main.c:3: In function 'memset', inlined from 'main' at main.c:68:3: /usr/include/x86_64-linux-gnu/bits/string3.h:90:10: warning: call to __builtin___memset_chk will always overflow destination buffer return __builtin___memset_chk (__dest, __ch, __len, __bos0 (__dest)); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~