Compilare: main.cpp: In function 'void bfs1(int)': main.cpp:24:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<graph[c_node].size();i++) ~^~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'void bfs2(int)': main.cpp:47:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<graph[c_node].size();i++) ~^~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:64:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("graf.in", "r", stdin); ^ main.cpp:65:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("graf.out", "w", stdout); ^ main.cpp:68:38: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &n, &m, &x, &y); ^ main.cpp:72:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &a, &b); ^