Compilare: main.cpp: In function 'int main()': main.cpp:40:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i <= n; i++) ~~^~~~ main.cpp:43:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i <= n; i++) { ~~^~~~ main.cpp: In function 'char nxt()': main.cpp:18:31: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, DIM, stdin); ^ main.cpp: In function 'int main()': main.cpp:37:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("secv5.in", "r", stdin); ^ main.cpp:38:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("secv5.out", "w", stdout); ^