Compilare: user.cpp: In function ‘bool Match(int)’: user.cpp:31:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<g[node].size();i++) ^ user.cpp:38:28: 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:93:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<permutations.size();i++){ ^ user.cpp:84:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("algebra.in","r",stdin); ^ user.cpp:85:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("algebra.out","w",stdout); ^ user.cpp:87:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:90:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf",&a[i][j]); ^