LC#300, finds majority element in array, O(N) time, O(N) Space

Author: NirmalSilwal

Leetcode/easy/MajorityElement169.java

@@ -0,0 +1,39 @@
+package easy;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class MajorityElement169 {
+
+	public static int majorityElement(int[] nums) {
+
+		HashMap<Integer, Integer> map = new HashMap<>();
+
+		for (int n : nums) {
+			if (!map.containsKey(n)) {
+				map.put(n, 1);
+			} else {
+				map.put(n, map.get(n) + 1);
+			}
+		}
+
+		double maxLimit = Math.ceil(nums.length / 2.0);
+		int ans = Integer.MAX_VALUE;
+
+		for (Map.Entry<Integer, Integer> entries : map.entrySet()) {
+			if (entries.getValue() >= maxLimit)
+				ans = entries.getKey();
+		}
+		return ans;
+	}
+
+	public static void main(String[] args) {
+		int[] nums = { 2, 2, 1, 1, 1, 2, 2 };
+		System.out.println(majorityElement(nums));
+
+		System.out.println(majorityElement(new int[] { 3, 2, 3 }));
+
+		System.out.println(majorityElement(new int[] { 2, 2 }));
+
+	}
+}