Compilare: main.cpp: In function 'bool Bellman_Ford(int, int)': main.cpp:41:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 0; i < V[ nod ].size(); ++i ) { ~~^~~~~~~~~~~~~~~~~ main.cpp:21:12: warning: unused variable 'j' [-Wunused-variable] int i, j; ^ main.cpp: In function 'int main()': main.cpp:60:44: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen( "bellmanford.in", "r", stdin ); ^ main.cpp:61:46: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen( "bellmanford.out", "w", stdout ); ^ main.cpp:67:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf( "%d%d", &n,&m ); ^ main.cpp:69:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf( "%d%d%d", &x,&y,&c ); ^