Majority element exercise (#6)

data-structures-and-algorithms/majority-element/answer/README.md

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+# Majority Element
+
+Find the majority element in a given array. The majority element in an array of size n is an element that appears more than n/2 times.
+
+Examples:
+
+```
+Input : arr = [3, 9, 2, 9, 2, 9, 9]
+Output : 9
+Explanation: n = 7. 9 appear more 4 times which is more than 7/2 times 
+
+Input : arr = [3]
+Output : 3
+Explanation: Appears more than n/2 times
+
+Input : arr = [3, 3, 4, 2, 4, 4, 2, 4]
+Output : null
+Explanation: There is no element whose frequency is greater than n/2
+```

data-structures-and-algorithms/majority-element/answer/majority-element.js

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+const assert = require('assert');
+
+function majorityElement(input) {
+  const found =  {};
+  input.forEach(n => {
+    if (found[n]) {
+      found[n]++;
+    } else {
+      found[n] = 1;
+    }
+  });
+
+  const minSize = input.length / 2;
+  for (k in found) {
+    if (found[k] > minSize) {
+      return k;
+    }
+  };
+
+  return null;
+}
+
+assert.equal(majorityElement([3, 9, 2, 9, 2, 9, 9]), 9);
+assert.equal(majorityElement([3]), 3);
+assert.equal(majorityElement([3, 3, 4, 2, 4, 4, 2, 4]), null);
+
+console.log("All assertions passed!");

data-structures-and-algorithms/majority-element/execise/README.md

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+# Majority Element
+
+Find the majority element in a given array. The majority element in an array of size n is an element that appears more than n/2 times.
+
+Examples:
+
+```
+Input : arr = [3, 9, 2, 9, 2, 9, 9]
+Output : 9
+Explanation: n = 7. 9 appear more 4 times which is more than 7/2 times 
+
+Input : arr = [3]
+Output : 3
+Explanation: Appears more than n/2 times
+
+Input : arr = [3, 3, 4, 2, 4, 4, 2, 4]
+Output : null
+Explanation: There is no element whose frequency is greater than n/2
+```

data-structures-and-algorithms/majority-element/execise/majority-element.js

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+const assert = require('assert');
+
+function majorityElement(input) {
+}
+
+assert.equal(majorityElement([3, 9, 2, 9, 2, 9, 9]), 9);
+assert.equal(majorityElement([3]), 3);
+assert.equal(majorityElement([3, 3, 4, 2, 4, 4, 2, 4]), null);
+
+console.log("All assertions passed!");