Compilare: main.cpp: In function 'void Dijkstra(std::vector<std::pair<int, int> >*, int)': main.cpp:31:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i = 0; i < V[ x ].size(); ++i ) { ~~^~~~~~~~~~~~~~~ main.cpp:18:12: warning: unused variable 'y' [-Wunused-variable] int x, y, c; ^ main.cpp:18:15: warning: unused variable 'c' [-Wunused-variable] int x, y, c; ^ main.cpp: In function 'int main()': main.cpp:45:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen( "dijkstra.in", "r", stdin ); ^ main.cpp:46:43: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen( "dijkstra.out", "w", stdout ); ^