C++ Program to Find Largest Number in an Array

Write a C++ program to find largest number in an array. Given an unsorted array, we have to write a C++ code to find the largest number in an array.

Let's think for a moment, how do you solve this problem. You can solve this problem using sorting algorithm, first sort an array and then pick the element at n-1 position. But, let's solve this problem without using any sorting algorithm.

Also, The time complexity of sorting an array is O(nlogn) but we can solve this problem in O(n) in a single traversal.

Algorithm to Find Largest Number in an Array

i) Take an input array from a user.

ii) Take a variable highest and assign first element of an array. After that traverse an array and compare each element of an array with highest. If any element is greater than the highest then assign that value into highest.


Sample snippet.

 /* Assign array first element to highest variable. */

   int highest = arr[0];

  /* Iterate till the end of an array. */
 
   for(i=1;i< arrcount; i++){
 
        /* Check if array element is higher
           than value in highest.*/
       
 if(arr[i]>highest){
   
        highest = arr[i];
     }
 }

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C program to find highest number in an array

C++ Program to Find Largest Number in an Array

#include <iostream>
using namespace std;

int main() {
    
    int arr[100], n, i, highest;
    
    cout << "Enter the size of an array( Max 100) \n";
    cin >> n;
    
    cout << "Enter array elements \n";
    
    //Take input values
    
    for(i = 0; i < n; i++) {
        cin >> arr[i];
    }
    
    
    //Assign first value 
    
    highest = arr[0];
    
    //Traverse an array
    
    for(i = 0; i < n; i++) {
        
        //If any value is greater than highest
        
        if(arr[i] > highest) {
            highest = arr[i];
        }
    }
    
    //Print largest number
    
    cout << "Largest number " << highest;
    
    return 0;
}

Output :

Enter the size of an array( Max 100)  5

Enter array elements
3
8
2
7
1

 Largest number 8


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