Compilare: user.cpp: In function ‘int BFS()’: user.cpp:20:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<g[node].size();i++){ ^ user.cpp: In function ‘int main()’: user.cpp:55:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<g[sink].size();i++){ ^ user.cpp:80:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<solution.size();i++) ^ user.cpp:37:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("croco.in","r",stdin); ^ user.cpp:38:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("croco.out","w",stdout); ^ user.cpp:40:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:43:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&capacity[i][j]); ^