Compilare: main.cpp: In function 'void unite(int)': main.cpp:35:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[idx].size();i++){ ~^~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:101:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<fr[lp].size();i++){ ~^~~~~~~~~~~~~~ main.cpp:107:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<fr[x].size();i++){ ~^~~~~~~~~~~~~ main.cpp:117:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<fr[lp].size();i++){ ~^~~~~~~~~~~~~~ main.cpp:71:30: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d",&n,&k); ^ main.cpp:73:40: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d",&val[i].first); ^ main.cpp:80:34: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d",&x,&y); ^