Create evenarray.cpp

Author: takkarparas

Algorithm/evenarray.cpp

@@ -0,0 +1,27 @@
+#include <iostream>
+#include <vector>
+using namespace std;
+int t,s,e,i;
+vector<int>v;
+int main()
+{   cin>>t;
+    while(t--)
+    {   
+        int a=0;
+        int b=0;
+        cin>>s;
+        for(i=0;i<s;i++)
+        {
+            cin>>e;
+
+            if((e%2)==0&(i%2)!=0)
+            {a+=1;}
+            if((e%2)!=0&(i%2)==0)
+            {b+=1;}
+        }
+        if(a==b)
+        {cout<<a<<"\n";}
+        else
+        {cout<<-1<<"\n";}
+    }
+}