Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:34:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<gf[node].size(); ++i){ ^ user.cpp:68:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i > 0 && i < fii.size()-1 ) dp[node][1] += (((prod * dp[vc][1] ) % MOD) * dreapta[i+1])%MOD; ^ user.cpp:69:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if (i == 0 && i < fii.size()-1) dp[node][1] += (((1LL*dreapta[i+1] * dp[vc][1] ) % MOD) ); ^ user.cpp:70:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(i > 0 && i == fii.size()-1)dp[node][1] += (((1LL*prod * dp[vc][1] ) % MOD) ); ^ user.cpp: In function ‘int main()’: user.cpp:83:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("karb2.in", "r", stdin); ^ user.cpp:84:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("karb2.out", "w", stdout); ^