Compilare: main.c: In function 'main': main.c:18:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation] for(i=2;i<=n;++i) ^~~ main.c:20:2: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for' D(1,0); ^ main.c:13:2: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("lca.in","r",stdin),freopen("lca.out","w",stdout),scanf("%d%d",&n,&m); ^~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:13:30: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("lca.in","r",stdin),freopen("lca.out","w",stdout),scanf("%d%d",&n,&m); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:13:60: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] freopen("lca.in","r",stdin),freopen("lca.out","w",stdout),scanf("%d%d",&n,&m); ^~~~~~~~~~~~~~~~~~~ main.c:15:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",c+i),++w[c[i]]; ^~~~~~~~~~~~~~~ main.c:32:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&i,&j),a=f[i],b=f[j]; ^~~~~~~~~~~~~~~~~~~