Compilare: user.cpp: In function ‘int main()’: user.cpp:29:37: warning: format ‘%s’ expects argument of type ‘char*’, but argument 4 has type ‘char (*)[260]’ [-Wformat=] scanf("%lld %lld %s\n",&x,&y,&ss); strcat(ss,"+"); ^ user.cpp:22:28: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mxl.in","r",stdin); ^ user.cpp:23:30: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mxl.out","w",stdout); ^ user.cpp:24:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld",&n,&m); ^ user.cpp:29:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld %lld %s\n",&x,&y,&ss); strcat(ss,"+"); ^