Add 673_Number_of_Longest_Increasing_Subsequence.java

Author: Sean Prashad

Dynamic Programming/673_Number_of_Longest_Increasing_Subsequence.java

@@ -0,0 +1,35 @@
+class Solution {
+ public int findNumberOfLIS(int[] nums) {
+ if (nums == null || nums.length == 0) {
+ return 0;
+ }
+
+ int[] dp = new int[nums.length], cnt = new int[nums.length];
+ Arrays.fill(dp, 1);
+ Arrays.fill(cnt, 1);
+
+ int result = 0, max = 1;
+
+ for (int i = 0; i < nums.length; i++) {
+ for (int j = 0; j < i; j++) {
+ if (nums[j] < nums[i]) {
+ if (dp[j] + 1 == dp[i]) {
+ cnt[i] += cnt[j];
+ } else if (dp[j] + 1 > dp[i]) {
+ dp[i] = dp[j] + 1;
+ cnt[i] = cnt[j];
+ }
+ }
+ }
+
+ if (dp[i] == max) {
+ result += cnt[i];
+ } else if (dp[i] > max) {
+ max = dp[i];
+ result = cnt[i];
+ }
+ }
+
+ return result;
+ }
+}