Compilare: main.cpp: In function 'int main()': main.cpp:22:9: warning: unused variable 't' [-Wunused-variable] int t; ^ main.cpp:23:13: warning: variable 'c' set but not used [-Wunused-but-set-variable] int a,b,c; ^ main.cpp:26:21: warning: variable 'na' set but not used [-Wunused-but-set-variable] long long x=0,y,na; ^~ main.cpp:20:42: 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:21:44: 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:25:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^