Majority Element in an Array (#1384)

Majority_Element/Majority_Element.c

@@ -0,0 +1,58 @@
+/*
+A majority element in an array arr of size n is an
+element that appears more than n/2 times.
+Example: 
+N = 9, arr = {1, 2, 2, 2, 4, 2, 2, 1, 5}
+Majority Element = 2 as count[2] = 5 which is greater
+than n/2 i.e 4
+*/
+
+#include<stdio.h>
+#define SIZE 1000007
+
+int checkMajorityElement(int arr[], int N)
+{
+    int freq[SIZE] = {0};
+    // Computing frequency of each element
+    for (int i = 0; i < N; i++)
+        freq[arr[i]]++;
+    for (int i = 0; i < SIZE; i++)
+    {
+        if (freq[i] != 0 && freq[i] > (N / 2))
+        return i;
+    }
+    return -1;
+}
+
+int main()
+{
+    int N;
+    printf("Enter size of array:\n");
+    scanf("%d", &N);
+    int arr[N];
+    printf("Enter elements of array:\n");
+    for (int i = 0; i < N; i++)
+        scanf("%d", &arr[i]);
+    int ans = checkMajorityElement(arr, N);
+    if (ans != -1)
+        printf("Majority Element is: %d", ans);
+    else
+        printf("No majority element in array");
+    return 0;
+}
+
+/*
+Input:
+N = 9
+arr = {1, 2, 2, 2, 4, 2, 2, 1, 5}
+
+Output:
+Majority Element is: 2
+
+Input:
+N = 5
+arr = {1, 2, 3, 4, 5}
+
+Output:
+No majority element in array
+*/

Majority_Element/Majority_Element.cpp

@@ -0,0 +1,59 @@
+/*
+A majority element in an array arr of size n is an
+element that appears more than n/2 times.
+Example: 
+N = 9, arr = {1, 2, 2, 2, 4, 2, 2, 1, 5}
+Majority Element = 2 as count[2] = 5 which is greater
+than n/2 i.e 4
+*/
+
+#include<bits/stdc++.h>
+using namespace std;
+
+int checkMajorityElement(int arr[], int N)
+{
+    map<int, int> mp;
+    // Computing frequency of each element using Map
+    for (int i = 0; i < N; i++)
+        mp[arr[i]]++;
+    map<int, int> :: iterator it;
+    for (it = mp.begin(); it != mp.end(); it++)
+    {
+        if (it -> second > (N / 2))
+        return it -> first;
+    }
+    return -1;
+}
+
+int main()
+{
+    int N;
+    cout<<"Enter size of array:"<<endl;
+    cin>>N;
+    int arr[N];
+    cout<<"Enter elements of array:"<<endl;
+    for (int i = 0; i < N; i++)
+        cin>>arr[i];
+    int ans = checkMajorityElement(arr, N);
+    if (ans != -1)
+        cout<<"Majority Element is: "<<ans<<endl;
+    else
+        cout<<"No majority element in array"<<endl;
+    return 0;
+}
+
+/*
+Input:
+N = 9
+arr = {1, 2, 2, 2, 4, 2, 2, 1, 5}
+
+Output:
+Majority Element is: 2
+
+Input:
+N = 5
+arr = {1, 2, 3, 4, 5}
+
+Output:
+No majority element in array
+*/

Majority_Element/Majority_Element.go

@@ -0,0 +1,59 @@
+/*
+A majority element in an array arr of size n is an
+element that appears more than n/2 times.
+Example: 
+N = 9, arr = {1, 2, 2, 2, 4, 2, 2, 1, 5}
+Majority Element = 2 as count[2] = 5 which is greater
+than n/2 i.e 4
+*/
+
+package main
+import "fmt"
+
+func checkMajorityElement(arr[] int, N int) int {
+    mp := make(map[int] int)
+    // Computing frequency of each element
+    for i := 0; i < N; i++ {
+        mp[arr[i]]++
+    }
+
+    for key, value := range mp {
+        if value > (N / 2) {
+            return key
+        }
+    }
+    return -1
+}
+
+func main() {
+    var N int
+    fmt.Printf("Enter size of array:\n")
+    fmt.Scanf("%d", &N)
+    arr := make([]int, N)
+    fmt.Printf("Enter elements of array:\n")
+    for i := 0; i < N; i++ {
+        fmt.Scanf("%d", &arr[i])
+    }
+    ans := checkMajorityElement(arr, N)
+    if ans != -1 {
+        fmt.Printf("Majority Element is: %d", ans)
+    } else {
+        fmt.Printf("No majority element in array")
+    }
+}
+
+/*
+Input:
+N = 9
+arr = {1, 2, 2, 2, 4, 2, 2, 1, 5}
+
+Output:
+Majority Element is: 2
+
+Input:
+N = 5
+arr = {1, 2, 3, 4, 5}
+
+Output:
+No majority element in array
+*/

Majority_Element/Majority_Element.java

@@ -0,0 +1,66 @@
+/*
+A majority element in an array arr of size n is an
+element that appears more than n/2 times.
+Example: 
+N = 9, arr = {1, 2, 2, 2, 4, 2, 2, 1, 5}
+Majority Element = 2 as count[2] = 5 which is greater
+than n/2 i.e 4
+*/
+
+import java.util.Scanner;
+import java.util.Map; 
+import java.util.HashMap; 
+
+class Majority_Element
+{
+    public static int checkMajorityElement(int arr[], int N)
+    {
+        Map<Integer, Integer> mp = new HashMap<Integer, Integer>();
+        // Computing frequency of each element using Map
+        for (int i = 0; i < N; i++) 
+        { 
+            if (mp.containsKey(arr[i]))
+                mp.put(arr[i], mp.get(arr[i]) + 1); 
+            else 
+                mp.put(arr[i], 1); 
+        } 
+        for (Map.Entry<Integer, Integer> entry : mp.entrySet())
+        {
+            if (entry.getValue() > (N / 2))
+            return entry.getKey();
+        }
+        return -1;
+    }
+
+    public static void main(String args[])
+    {
+        Scanner sc = new Scanner(System.in);
+        System.out.println("Enter size of array:");
+        int N = sc.nextInt();
+        int arr[] = new int[N];
+        System.out.println("Enter elements of array:");
+        for (int i = 0; i < N; i++)
+            arr[i] = sc.nextInt();
+        int ans = checkMajorityElement(arr, N);
+        if (ans != -1)
+            System.out.println("Majority Element is: " + ans);
+        else
+            System.out.println("No majority element in array");
+    }
+}
+
+/*
+Input:
+N = 9
+arr = {1, 2, 2, 2, 4, 2, 2, 1, 5}
+
+Output:
+Majority Element is: 2
+
+Input:
+N = 5
+arr = {1, 2, 3, 4, 5}
+
+Output:
+No majority element in array
+*/

Majority_Element/Majority_Element.py

@@ -0,0 +1,49 @@
+'''
+A majority element in an array arr of size n is an
+element that appears more than n/2 times.
+Example: 
+N = 9, arr = {1, 2, 2, 2, 4, 2, 2, 1, 5}
+Majority Element = 2 as count[2] = 5 which is greater
+than n/2 i.e 4
+'''
+
+def checkMajorityElement(arr, N):
+    mp = {}
+    # Computing frequency of each element using Map
+    for i in range(0, N):
+        if arr[i] in mp.keys(): 
+            mp[arr[i]] += 1
+        else: 
+            mp[arr[i]] = 1
+
+    # iterating over map
+    for key in mp:
+        if mp[key] > (N / 2):
+            return key
+    return -1
+
+print("Enter size of array:")
+N = int(input())
+print("Enter elements of array:")
+arr = [int(x) for x in input().split(' ')]
+ans = checkMajorityElement(arr, N)
+if ans != -1:
+    print("Majority Element is: %d" % ans)
+else:
+    print("No majority element in array")
+
+'''
+Input:
+N = 9
+arr = {1, 2, 2, 2, 4, 2, 2, 1, 5}
+
+Output:
+Majority Element is: 2
+
+Input:
+N = 5
+arr = {1, 2, 3, 4, 5}
+
+Output:
+No majority element in array
+'''