Update Solution.java

Author: Jerring

solution/1155.Number of Dice Rolls With Target Sum/Solution.java

@@ -4,6 +4,10 @@ public int numRollsToTarget(int d, int f, int target) {
         dp[0][0] = 1;
         for (int i = 1; i <= d; ++i) {
             for (int j = 1; j <= target; ++j) {
+                // j 大于当前所有骰子的最大和，不可能满足条件
+                if (j > i * f) {
+                    break;
+                }
                 for (int k = 1; k <= f && k <= j; ++k) {
                     dp[i][j] = (dp[i][j] + dp[i - 1][j - k]) % 1000000007;
                 }