Compilare: user.cpp: In function ‘int pereche(int)’: user.cpp:11:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<l[x].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:30:28: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&n,&m); ^ user.cpp:36:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&x); ^ user.cpp:40:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%c",&c); ^