Clinic #15 - Number of Islands

Pattern: Graph Traversal (grid flood-fill) · LC 200

Naksha mein har khaana zameen ya paani hai, aur board dikhata hai ki paas-paas ki zameen mil kar kaise ek hi tapu ban jaati hai - poora sabak isi ek observation par khada hai.

Before you start. Isse pehle sirf itna chahiye: ek 2D grid (row aur column wala jaal) ka har khaana grid[r][c] se milta hai, jahan r row hai aur c column. Aur ek chhota sa idea saath rakho - ek kaam ko chhote-chhote tukdon mein tod kar, wahi kaam khud dobara karna, jab tak koi tukda bacha na ho - baaki sab is lesson ke andar hi samjha diya jaayega.