Ayush and children

CodeChefOpen on judge ↗

It's Ayush's birthday today and he wants to give candies to his friends. There are N students, numbered 1,2,…,N in his class. He has total K candies . He has decided not to keep any candy to himself . Here, for each i (1≤i≤N), his i-th friend must receive between 0 and ai candies (inclusive). Also, no candies should be left over. Find the number of ways for him to offer candies, modulo 10^9+7. H

HINT LADDERno hints yet

L1 Observation

L2 Technique

L3 Approach

L4 Pseudo-code

🔒

L5 Full solution

L5 unlocks only if you insist twice

solution.cppC++17

CodeSearch Tutor

Hints, not spoilers — it won’t hand over the full solution unless you insist.

voice by Sarvam AI