#6 DP
- When observed, you will find the problem to have recurring optimal subproblems.
- Start with solving the problem with recursion, observe the changing variables and develop a formula out of it.
#5 Recursion
- When you need to explore every path to lead to the result. But what does exploring every path means? It means at every iteration you will have choices and eventually, some decisions to make. And those decisions will lead to the solution.