Compilare: user.cpp: In function ‘int lca(int, int, int)’: user.cpp:15:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[r].size();i++)v[i][r]=lca(v[i][r],a,b); ^ user.cpp:16:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[r].size();i++)if(v[a][i]==inf)temp++; ^ user.cpp:17:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(temp==v[r].size())return inf; ^ user.cpp:18:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:28:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:31:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^ user.cpp:34:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&p); ^ user.cpp:37:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^ user.cpp: In function ‘int lca(int, int, int)’: user.cpp:17:2: warning: ‘temp’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(temp==v[r].size())return inf; ^