Class Solution


  • public class Solution
    extends Object
    1223 - Dice Roll Simulation.

    Hard

    A die simulator generates a random number from 1 to 6 for each roll. You introduced a constraint to the generator such that it cannot roll the number i more than rollMax[i] ( 1-indexed ) consecutive times.

    Given an array of integers rollMax and an integer n, return the number of distinct sequences that can be obtained with exact n rolls. Since the answer may be too large, return it modulo 109 + 7.

    Two sequences are considered different if at least one element differs from each other.

    Example 1:

    Input: n = 2, rollMax = [1,1,2,2,2,3]

    Output: 34

    Explanation: There will be 2 rolls of die, if there are no constraints on the die, there are 6 * 6 = 36 possible combinations. In this case, looking at rollMax array, the numbers 1 and 2 appear at most once consecutively, therefore sequences (1,1) and (2,2) cannot occur, so the final answer is 36-2 = 34.

    Example 2:

    Input: n = 2, rollMax = [1,1,1,1,1,1]

    Output: 30

    Example 3:

    Input: n = 3, rollMax = [1,1,1,2,2,3]

    Output: 181

    Constraints:

    • 1 <= n <= 5000
    • rollMax.length == 6
    • 1 <= rollMax[i] <= 15
    • Constructor Detail

      • Solution

        public Solution()
    • Method Detail

      • dieSimulator

        public int dieSimulator​(int n,
                                int[] rollMax)