Compilare: main.cpp: In function 'int main()': main.cpp:33:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k=0; k<nd[j].size(); k++) ~^~~~~~~~~~~~~ main.cpp:16:28: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d%d",&n,&m); ^ main.cpp:19:37: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d%d%d",&a,&b,&c); ^