Create 1524.Number-of-Sub-arrays-With-Odd-Sum.cpp

thisistrue1 · Jul 2, 2021 · 9244709 · 9244709
1 parent a9c71b7
commit 9244709
Showing 1 changed file with 24 additions and 0 deletions.
diff --git a/Hash/1524.Number-of-Sub-arrays-With-Odd-Sum/1524.Number-of-Sub-arrays-With-Odd-Sum.cpp b/Hash/1524.Number-of-Sub-arrays-With-Odd-Sum/1524.Number-of-Sub-arrays-With-Odd-Sum.cpp
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+class Solution {
+public:
+    int numOfSubarrays(vector<int>& arr) 
+    {
+        int presum = 0;
+        long odd = 0, even  = 1;
+        long ret = 0;
+        long M = 1e9+7;
+        for (int x : arr)
+        {
+            presum+=x;
+            if (presum%2==0)
+                ret = (ret+odd)%M;
+            else
+                ret = (ret+even)%M;
+            if (presum%2==0)
+                even+=1;
+            else
+                odd+=1;
+        }
+        return ret;
+
+    }
+};