Compilare: user.cpp:13:0: warning: "M_PI" redefined #define M_PI 3.14159 In file included from /usr/include/c++/6/cmath:45:0, from user.cpp:2: /usr/include/math.h:418:0: note: this is the location of the previous definition # define M_PI 3.14159265358979323846 /* pi */ user.cpp: In function ‘int main()’: user.cpp:57:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<v.size();i++){ ~^~~~~~~~~ user.cpp:80:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=2;i<vf.size();i++){ ~^~~~~~~~~~ user.cpp:45:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("perfect2.in","r",stdin); ^ user.cpp:46:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("perfect2.out","w",stdout); ^ user.cpp:48:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&cr,&n); ^ user.cpp:50:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&tx,&ty); ^