Compilare: main.cpp: In function 'int main()': main.cpp:41:9: warning: variable 'k' set but not used [-Wunused-but-set-variable] int n, k; ^ main.cpp:39:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("placute.in", "r", stdin); ^ main.cpp:40:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("placute.out", "w", stdout); ^ main.cpp: In function 'char next()': main.cpp:10:39: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buffer, 1, BUFFER_SIZE, stdin); ^