Compilare: main.cpp: In function 'int main()': main.cpp:29:44: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("inversmodular.in", "r", stdin); ^ main.cpp:30:46: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("inversmodular.out", "w", stdout); ^ main.cpp:32:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &a, &n); ^ main.cpp:36:11: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized] printf("%d\n", x % n); ~~~~~~^~~~~~~~~~~~~~~