Compilare: main.cpp: In function 'int main()': main.cpp:32:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[nod].size();i++){ ~^~~~~~~~~~~~~~ main.cpp:42:39: warning: format '%d' expects argument of type 'int', but argument 3 has type 'std::vector<std::pair<int, int> >::size_type {aka long unsigned int}' [-Wformat=] printf("%d\n%d\n",cost,sol.size()-1); ^ main.cpp:43:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i<sol.size();i++) printf("%d %d\n",sol[i].f,sol[i].s); ~^~~~~~~~~~~ main.cpp:15:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("apm.in","r",stdin); ^ main.cpp:16:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("apm.out","w",stdout); ^ main.cpp:17:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ main.cpp:18:48: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] for(i=1;i<=m;i++) {scanf("%d%d%d",&x,&y,&z); ^