adding Largest Common Subsequence and eslint

Author: smishr4

.eslintrc.js

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+module.exports = {
+  env: {
+    es6: true,
+    jest: true,
+    node: true
+  },
+  rules: {
+    "no-undef": "error",
+    "no-unused-vars": "warn",
+    "no-console": "warn"
+  },
+  extends: ["eslint:recommended"]
+};

.gitignore

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+node_modules

.vscode/settings.json

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+{
+  "editor.tabSize": 2
+}

LargestCommonSubarray.js

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+function LargestCommonSubarray(a, b) {
+  const m = a.length,
+    n = b.length;
+
+  let max = [];
+
+  // make a 2d array d of size m,n with all blank arrays
+  // double loop(i,j) on a and b
+  // d[i][j] = d[i-1][j-1].concat(a[i]) if a[i] == b[i]
+
+  const d = Array(m)
+    .fill()
+    .map(() =>
+      Array(n)
+        .fill()
+        .map(() => [])
+    );
+
+  for (let i = 0; i < m; i++) {
+    for (let j = 0; j < n; j++) {
+      if (a[i] == b[j]) {
+        if (i > 0 && j > 0) {
+          d[i][j] = d[i - 1][j - 1].concat(a[i]);
+        } else {
+          d[i][j] = [a[i]];
+        }
+      }
+      max = d[i][j].length > max.length ? d[i][j] : max;
+    }
+  }
+  // console.log(d);
+  return max;
+}
+
+function lengthLargestCommonSubarray(A, B) {
+  var m = A.length,
+    n = B.length;
+  var d = new Array(m).fill().map(() => new Array(n).fill(0));
+  d[0][0] = A[0] == B[0] ? 1 : 0;
+  d[0][1] = 0;
+  d[1][0] = 0;
+
+  let max = Number.MIN_SAFE_INTEGER;
+
+  for (var i = 0; i < m; i++) {
+    for (var j = 0; j < n; j++) {
+      if (A[i] == B[j]) {
+        if (i <= 0 || j <= 0) {
+          d[i][j] = 1;
+        } else {
+          d[i][j] = d[i - 1][j - 1] + 1;
+        }
+      }
+      max = d[i][j] > max ? d[i][j] : max;
+    }
+  }
+  return max;
+}
+
+const A = [1, 2, 3, 2, 1],
+  B = [3, 2, 1, 4, 7];
+
+// eslint-disable-next-line
+console.log(LargestCommonSubarray(A, B), lengthLargestCommonSubarray(A, B));

package.json

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+{
+  "name": "practice",
+  "version": "1.0.0",
+  "description": "Problem solving with js",
+  "main": "index.js",
+  "repository": "git@github.com:smishr4/practice.git",
+  "author": "shubham <shubhammshr621@gmail.com>",
+  "license": "MIT",
+  "dependencies": {},
+  "devDependencies": {
+    "eslint": "^5.16.0"
+  }
+}