Compilare: main.cpp: In function 'int main()': main.cpp:93:7: warning: variable 'r' set but not used [-Wunused-but-set-variable] int r, c, n; ^ main.cpp:93:10: warning: variable 'c' set but not used [-Wunused-but-set-variable] int r, c, n; ^ main.cpp: In function 'int u32()': main.cpp:28:30: 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, LEN, stdin); ^ main.cpp:35:30: 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, LEN, stdin); ^ main.cpp: In function 'int main()': main.cpp:90:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("trampoline.in", "r", stdin); ^ main.cpp:91:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("trampoline.out", "w", stdout); ^