Compilare: user.cpp: In function ‘void do_divide(const std::vector<int>&, int)’: user.cpp:25:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<tmp.size();j++) ^ user.cpp: At global scope: user.cpp:30:6: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type] main(){ ^ user.cpp: In function ‘int main()’: user.cpp:41:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0;k<v[i][j].size();k++) ^ user.cpp:32:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("copii2.in","r",stdin); ^ user.cpp:33:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("copii2.out","w",stdout); ^ user.cpp:34:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&N,&K); ^