Compilare: main.cpp: In function 'int main()': main.cpp:27:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("xor.in", "r", stdin); ^ main.cpp:28:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("xor.out", "w", stdout); ^ main.cpp:30:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &tt, &mod); ^ main.cpp:37:43: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d", &l1, &c1, &l2, &c2); ^