Yes it's DCFL.
1. Push all a's and b's
2. if c comes, then ignore this c and pop all the b's
3. when a's come again, pop one 'a' from stack for every input 'a'
4. input is completed and stack contains stack contains stack symbol on TOS, accept the language.
1. Push all a's and b's
2. if d comes, then ignore this d
3. when b's come again, pop one 'b' from stack for every input 'b'
4. input is completed and stack contains 'a' on the top of the stack, then accept the language