Compilare: user.cpp: In function ‘int Solve(std::vector<int>, std::vector<int>)’: user.cpp:24:11: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(b[i]!=-1&&c[line][i]!=b[i]) ^ user.cpp:9:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,line=-1,answer=1,forced=-1; ^ user.cpp: In function ‘int main()’: user.cpp:57:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("entanglement.in","r",stdin); ^ user.cpp:58:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("entanglement.out","w",stdout); ^ user.cpp:60:44: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&requirement,&n,&m,&k); ^ user.cpp:63:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&c[i][j]); ^