Merge pull request #400 from yang170/patch-6

Update 0115.不同的子序列.md

problems/0115.不同的子序列.md

@@ -145,7 +145,28 @@ public:
 
 
 Java：
+```java
+class Solution {
+    public int numDistinct(String s, String t) {
+        int[][] dp = new int[s.length() + 1][t.length() + 1];
+        for (int i = 0; i < s.length() + 1; i++) {
+            dp[i][0] = 1;
+        }
         
+        for (int i = 1; i < s.length() + 1; i++) {
+            for (int j = 1; j < t.length() + 1; j++) {
+                if (s.charAt(i - 1) == t.charAt(j - 1)) {
+                    dp[i][j] = dp[i - 1][j - 1] + dp[i - 1][j];
+                }else{
+                    dp[i][j] = dp[i - 1][j];
+                }
+            }
+        }
+        
+        return dp[s.length()][t.length()];
+    }
+}
+```
 
 Python：
 ```python