kadane_algo added in L-I (#51)

Author: 007aneesh

L-I/0010 Kadanes_algorithm/README.md

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+Name : Aneesh
+Github username : 007aneesh
+Repository name : data-structures-and-algorithms
+Problem : Kadane's algorithm in Javascript
+Issue Number : #1182
+Problem statement : Given an integer array nums, find the subarray with the largest sum, and return its sum.
+
+Sample testcases:
+
+Testcase 1 -->
+
+Input: number of elements in array = 9
+nums = [-2,1,-3,4,-1,2,1,-5,4]
+Output: 6
+
+Testcase 2 -->
+Input: number of elements in array
+nums = [5,4,-1,7,8]
+Output: 23
+
+Time Complexity = O(n)
+Space Complexity = O(n)
+
+Explanation:
+This code asks the user to enter the number of elements in an array,
+and then prompts them to enter each element of the array one at a time.
+Once the array is complete, the code applies the Kadane's algorithm to
+find the maximum sum of any subarray within the array, and then prints
+the result to the console.
+
+Kadane's algorithm is a way of finding the maximum sum of a contiguous subarray within an array,
+and it does so by keeping track of the maximum sum seen so far as it iterates through the array.
+At each step, it adds the current element to a running sum, and if that sum becomes negative,
+it resets the running sum to zero. If the running sum is ever greater than the maximum seen so far,
+it updates the maximum. Finally, it returns the maximum sum.
+

L-I/0010 Kadanes_algorithm/kadane_algorithm.js

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+// ----------------------------------------------------------------------------- code begins now!
+const readline = require("readline");
+
+function kadaneAlgorithm(arr) {
+  if (!arr) return 0;
+  let sum = 0;
+  let max = 0;
+
+  for (let i = 0; i < arr.length; i++) {
+    max += arr[i];
+
+    if (max < 0) {
+      max = 0;
+    }
+
+    if (sum < max) {
+      sum = max;
+    }
+  }
+
+  return sum;
+}
+
+const rl = readline.createInterface({
+  input: process.stdin,
+  output: process.stdout,
+});
+
+let arr = [];
+
+rl.question("Enter number of elements in the array: ", function (n) {
+  let count = 0;
+
+  function getArrayInput() {
+    if (count < n) {
+      rl.question("Enter element in array: ", function (input) {
+        arr.push(Number(input));
+        count++;
+        getArrayInput();
+      });
+    } else {
+      let ans = kadaneAlgorithm(arr);
+      console.log(ans);
+      rl.close();
+    }
+  }
+
+  getArrayInput();
+});