Merge pull request #653 from ranaakash/master

Kadanes algorithm properly implemented with guidelines  issue #651

Algorithms/Arrays/Kadane/cpp-kadane'salgorithm-O(n)-2.cpp

@@ -0,0 +1,53 @@
+///Lets do Kadane's Algorithm
+///It is used to find largest sum in continous sub-array, for an array
+///The following program also gives index of the array obtained ( for 0 based index)
+///Explaination:https://hackernoon.com/kadanes-algorithm-explained-50316f4fd8a6
+
+#include<iostream>
+using namespace std;
+
+int main()
+{
+    int sumcurrent=0 , maxsum = 0,k=0,j=0 ,x = -1;
+    int n;
+    cout<<"Enter size of array"<<endl;
+    cin>>n;
+    int a[n];
+    cout<<"enter elements "<<endl;
+    for(int i=0;i<n;i++)
+    {
+        cin>>a[i];
+    }
+
+    for(int i=0;i<n;i++)
+    {
+        int temp = a[i];
+        ///cout<<" sumcurrent+ a[i] is "<<sumcurrent+a[i]<<endl;
+        if((sumcurrent+a[i])>=0)
+        {
+            sumcurrent = sumcurrent +a[i];
+        }
+        else
+        {
+            sumcurrent = 0;
+            x = i+1;
+        }
+        if(sumcurrent>maxsum)   ///Will only enter when when largest sum obtained
+        {
+            maxsum = sumcurrent ;
+            j = i;
+            if(x>=0)
+            {
+                k=x;
+            }
+        }
+
+    }
+
+    cout<<" maxsum is "<<endl;
+    cout<<maxsum<<endl;
+
+    cout<<" first and last index are "<<k<<" and "<<j<<endl;
+
+    return 0;
+}