I am Listing below the concepts I have used whilst solving the questions.

PROBLEMS

CONCEPTS USED

Frog 1 Classical DP Approach, Bottom Up DP
Frog 2 Classical DP Approach, Bottom Up DP
Vacation Bottom Up DP
Knapsack 1 Classical DP Approach, Top Down DP
Knapsack 2 Classical DP (with a twist), Bottom Up DP
LCS Top Down DP Approach
Longest Path
Grid 1 Grid DP, Bottom Up DP
Coins Probability DP, Bottom Up DP(Hard), Top Down DP(Easy)
Sushi Expected Value DP, Mathematics
Stones Game Theory and DP
Deque Game Theory and Multi-dimensional DP
Candies Multidimensional DP optimisation
Slimes DP over intervals
Matching DP + Bitmasking
Independent Set
Flowers
Walk
Digit Sum Digit DP