Compilare: user.cpp: In function ‘int main()’: user.cpp:120:46: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("symmetricgraph2.in", "r", stdin); ^ user.cpp:121:48: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("symmetricgraph2.out", "w", stdout); ^ user.cpp:123:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:126:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&c); ^ user.cpp:159:24: warning: ‘flux’ may be used uninitialized in this function [-Wmaybe-uninitialized] int coresp,flux; ^ user.cpp:167:33: warning: ‘coresp’ may be used uninitialized in this function [-Wmaybe-uninitialized] vaz[i]=vaz[coresp]=1; ^