Counting Dice Rolls — Solution & Editorial
A DP over (dice used, running sum) is O(D·T·F); the inclusion–exclusion formula ∑(−1)jC(D,j)C(T−jF−1, D−1) is O(T/F).
Complexity: O(D·T·F) or O(D)
A DP over (dice used, running sum) is O(D·T·F); the inclusion–exclusion formula ∑(−1)jC(D,j)C(T−jF−1, D−1) is O(T/F).
Complexity: O(D·T·F) or O(D)