Create Solution.java

Author: Jerring

solution/0673.Number of Longest Increasing Subsequence/Solution.java

@@ -0,0 +1,33 @@
+class Solution {
+    public int findNumberOfLIS(int[] nums) {
+        if (nums == null || nums.length == 0) {
+            return 0;
+        }
+        int n = nums.length;
+        int[] dp = new int[n];
+        int[] f = new int[n];
+        Arrays.fill(dp, 1);
+        Arrays.fill(f, 1);
+        int max = 0;
+        for (int i = 0; i < n; ++i) {
+            for (int j = 0; j < i; ++j) {
+                if (nums[i] > nums[j]) {
+                    if (dp[j] + 1 > dp[i]) {
+                        dp[i] = dp[j] + 1;
+                        f[i] = f[j];
+                    } else if (dp[j] + 1 == dp[i]) {
+                        f[i] += f[j];
+                    }
+                }
+            }
+            max = Math.max(max, dp[i]);
+        }
+        int res = 0;
+        for (int i = 0; i < n; ++i) {
+            if (dp[i] == max) {
+                res += f[i];
+            }
+        }
+        return res;
+    }
+}