Compilare: main.cpp: In function 'void bfs(int, int)': main.cpp:24:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<g[u].size(); i++) ~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:53:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j<g[i].size(); j++) ~^~~~~~~~~~~~ main.cpp:35:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] { freopen("marmelada.in", "r", stdin); ^ main.cpp:36:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("marmelada.out", "w", stdout); ^ main.cpp:38:40: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &n, &m, &xx, &yy); ^ main.cpp:40:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^ main.cpp:45:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &lung[i]); ^