catinatree.cpp: In function 'std::deque<int> d(int)':
catinatree.cpp:3:148: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
3 | using namespace std;int N,D,x,q,i;deque<int>c[1<<20];deque<int>d(int u){deque<int>q(1,1);for(int v:c[u]){auto a=d(v);if(q.z<a.z)swap(q,a);for(i=0;i<a.z;i++)q[i]=max(q[i],max(a[i]+(D-i<q.z?q[max(D-i,i)]:0),q[i]+(D-i<a.z?a[max(D-i,i)]:0)));for(i=a.z;i>=0;i--)if(i+1<q.z)q[i]=max(q[i],q[i+1]);}q.push_front(q.front());return q;}int main(){cin>>N>>D;for(i=1;i<N;i++){cin>>x;c[x].push_back(i);}for(int r:d(0))q=max(q,r);cout<<q;}
| ^
catinatree.cpp:3:184: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
3 | using namespace std;int N,D,x,q,i;deque<int>c[1<<20];deque<int>d(int u){deque<int>q(1,1);for(int v:c[u]){auto a=d(v);if(q.z<a.z)swap(q,a);for(i=0;i<a.z;i++)q[i]=max(q[i],max(a[i]+(D-i<q.z?q[max(D-i,i)]:0),q[i]+(D-i<a.z?a[max(D-i,i)]:0)));for(i=a.z;i>=0;i--)if(i+1<q.z)q[i]=max(q[i],q[i+1]);}q.push_front(q.front());return q;}int main(){cin>>N>>D;for(i=1;i<N;i++){cin>>x;c[x].push_back(i);}for(int r:d(0))q=max(q,r);cout<<q;}
| ^
catinatree.cpp:3:215: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
3 | using namespace std;int N,D,x,q,i;deque<int>c[1<<20];deque<int>d(int u){deque<int>q(1,1);for(int v:c[u]){auto a=d(v);if(q.z<a.z)swap(q,a);for(i=0;i<a.z;i++)q[i]=max(q[i],max(a[i]+(D-i<q.z?q[max(D-i,i)]:0),q[i]+(D-i<a.z?a[max(D-i,i)]:0)));for(i=a.z;i>=0;i--)if(i+1<q.z)q[i]=max(q[i],q[i+1]);}q.push_front(q.front());return q;}int main(){cin>>N>>D;for(i=1;i<N;i++){cin>>x;c[x].push_back(i);}for(int r:d(0))q=max(q,r);cout<<q;}
| ^
catinatree.cpp:3:264: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
3 | using namespace std;int N,D,x,q,i;deque<int>c[1<<20];deque<int>d(int u){deque<int>q(1,1);for(int v:c[u]){auto a=d(v);if(q.z<a.z)swap(q,a);for(i=0;i<a.z;i++)q[i]=max(q[i],max(a[i]+(D-i<q.z?q[max(D-i,i)]:0),q[i]+(D-i<a.z?a[max(D-i,i)]:0)));for(i=a.z;i>=0;i--)if(i+1<q.z)q[i]=max(q[i],q[i+1]);}q.push_front(q.front());return q;}int main(){cin>>N>>D;for(i=1;i<N;i++){cin>>x;c[x].push_back(i);}for(int r:d(0))q=max(q,r);cout<<q;}
| ^