Compilare: main.cpp: In function 'int lca(int, int)': main.cpp:39:9: warning: unused variable 'ans' [-Wunused-variable] int ans = 0; ^~~ main.cpp: In function 'int main()': main.cpp:116:55: warning: suggest parentheses around '-' inside '>>' [-Wparentheses] printf("%d\n",depth[v[a][b]] + depth[v[x][y]] - (depth[lca(v[a][b],v[x][y])]<<1 )>>1 ); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.cpp:65:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pirati.in","r",stdin); ^ main.cpp:66:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pirati.out","w",stdout); ^ main.cpp:67:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d",&n,&m,&q); ^ main.cpp:115:41: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d",&a,&b,&x,&y); ^