longest palindrome in a string alternative odd even nos by 2 threads lift question - less starvation and max utilisation longest sub array having unique characters stock prices of different vendors are coming in then get the best prices at any point of time. What would happen if a new price of vendor comes up, it should still give the best price at that time. - USE 2 stacks - 1 stack for the input at every input in stack 1 place the min element at that time in another stack. If the same vendor comes again with some new price just place it on stack 1 and get the min value at that time and place it in stack 2.