Compilare: user.cpp: In function ‘void solve1()’: user.cpp:21:44: warning: format ‘%s’ expects argument of type ‘char*’, but argument 2 has type ‘char (*)[30]’ [-Wformat=] for(int i=1;i<=n; ++i) scanf("%s",&s[i]); ^ user.cpp:20:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%lld",&n,&m); ^ user.cpp:21:45: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int i=1;i<=n; ++i) scanf("%s",&s[i]); ^ user.cpp: In function ‘void solve3()’: user.cpp:49:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%lld",&n,&m); ^ user.cpp:50:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i=1;i<=n;++i) scanf("%lld",&v[i]); ^ user.cpp: In function ‘int main()’: user.cpp:68:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("march.in","r",stdin); ^ user.cpp:69:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("march.out","w",stdout); ^ user.cpp:70:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&v); ^