Clinic #14 - Combination Sum

Pattern: Backtracking + Pruning · LC 39

Yeh drawing wahi pedh dikhati hai jo pichli clinic mein tha - chuno, aage jao, wapas aao - bas ab har shaakha par ek shart hai, aur toot-te hi turant kaat di jaati hai.

Before you start. Clinic #13 - Subsets mein ek pedh dekha tha: har number ke liye chuno ya chodo, phir agla number, aur ek pura rasta ban jaaye toh wapas aakar doosra try karo - isi ko backtracking kehte hain. Yahan wahi pedh hai, bas do naye niyam hain: ek number dobara liya ja sakta hai, aur kuch rastay beech mein hi chodne padte hain.