Here is my approach :
- Calculate All pairs shortest distance using floyd Warshall for every pair of cell.
- Then dp[subset] = optimal answer for this subset.
- For each tyger u 
subset try to connect that with this subset in minimal way using pre-calculated shortest distances such that dp[subset 
u] = dp[subset] + min_dis.
- At last take sum for all subsets.
But this gives wrong answer. Please help.
Can someone tell me the approach to solve this problem ?
