Compilare: main.cpp: In function 'int main()': main.cpp:24:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (k = 0 ; k < g[i].size() ; k++){ ~~^~~~~~~~~~~~~ main.cpp:37:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (k = 0 ; k < g[j].size() ; k++){ ~~^~~~~~~~~~~~~ main.cpp:44:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (k = 0 ; k < g[i].size() ; k++){ ~~^~~~~~~~~~~~~ main.cpp:14:30: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d",&f,&t); ^ main.cpp:16:53: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d",&v[i].first,&v[i].second); ^