Compilare: main.cpp: In function 'int main()': main.cpp:22:33: 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:23:35: 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:25:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d", &t, &MOD); ^ main.cpp:28:43: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d%d%d", &x1, &y1, &x2, &y2); ^