Compilare: user.cpp: In function ‘char nextch(FILE*)’: user.cpp:15:31: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, BUF_SIZE, 1, f); ^ user.cpp: In function ‘int main()’: user.cpp:57:30: warning: ‘r’ may be used uninitialized in this function [-Wmaybe-uninitialized] fprintf(f, "%d %d %d\n", r - k + 2, r + 1, ans); ^