Compilare: main.cpp: In function 'int main()': main.cpp:46:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<g[u].size(); i++){ ~^~~~~~~~~~~~ main.cpp:18:20: warning: unused variable 'u' [-Wunused-variable] int n,i,nr,l,j,u,maxx=0,nn; ^ main.cpp:16:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] { freopen("drum2.in", "r", stdin); ^ main.cpp:17:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("drum2.out", "w",stdout); ^ main.cpp:19:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:23:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &dist[i].cost); ^