Compilare: user.cpp: In function ‘void sol()’: user.cpp:68:30: warning: format ‘%ld’ expects argument of type ‘long int’, but argument 2 has type ‘std::vector<std::vector<long int> >::size_type {aka unsigned int}’ [-Wformat=] printf("%ld\n",res.size()); ^ user.cpp:69:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(long i = 0;i < res.size();++i){ ^ user.cpp:70:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(long j = 0;j < res[i].size();++j)printf("%ld ",res[i][j] + 1); ^ user.cpp: In function ‘int main()’: user.cpp:20:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.in","r",stdin); ^ user.cpp:21:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.out","w",stdout); ^ user.cpp: In function ‘void read()’: user.cpp:32:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld ",&n,&m); ^ user.cpp:35:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld ",&x,&y); ^