Create ways-to-split-array-into-good-subarrays.cpp

Author: kamyu104

C++/ways-to-split-array-into-good-subarrays.cpp

@@ -0,0 +1,21 @@
+// Time:  O(n)
+// Space: O(1)
+
+// combinatorics
+class Solution {
+public:
+    int numberOfGoodSubarraySplits(vector<int>& nums) {
+        static const int MOD = 1e9 + 7;
+        int result = 1, prev = -1;
+        for (int i = 0; i < size(nums); ++i) {
+            if (nums[i] != 1) {
+                continue;
+            }
+            if (prev != -1) {
+                result = (result * static_cast<int64_t>(i - prev)) % MOD;
+            }
+            prev = i;
+        }
+        return prev != -1 ? result : 0;
+    }
+};