java.lang.Object
g1101_1200.s1155_number_of_dice_rolls_with_target_sum.Solution

public class Solution extends Object
1155 - Number of Dice Rolls With Target Sum\. Medium You have `n` dice and each die has `k` faces numbered from `1` to `k`. Given three integers `n`, `k`, and `target`, return _the number of possible ways (out of the_ kn _total ways)_ _to roll the dice so the sum of the face-up numbers equals_ `target`. Since the answer may be too large, return it **modulo** 109 + 7. **Example 1:** **Input:** n = 1, k = 6, target = 3 **Output:** 1 **Explanation:** You throw one die with 6 faces. There is only one way to get a sum of 3. **Example 2:** **Input:** n = 2, k = 6, target = 7 **Output:** 6 **Explanation:** You throw two dice, each with 6 faces. There are 6 ways to get a sum of 7: 1+6, 2+5, 3+4, 4+3, 5+2, 6+1. **Example 3:** **Input:** n = 30, k = 30, target = 500 **Output:** 222616187 **Explanation:** The answer must be returned modulo 109 + 7. **Constraints:** * `1 <= n, k <= 30` * `1 <= target <= 1000`
  • Constructor Details

    • Solution

      public Solution()
  • Method Details

    • numRollsToTarget

      public int numRollsToTarget(int n, int k, int target)