using set in c++ to find largest element smaller than k code example

Example 1: how to get the largest number in a c++ array

#include <iostream>
using namespace std;
int main(){
   //n is the number of elements in the array
   int n, largest;
   int num[50];
   cout<<"Enter number of elements you want to enter: ";
   cin>>n;
   
   /* Loop runs from o to n, in such a way that first
    * element entered by user is stored in num[0], second 
    * in num[1] and so on. 
    */
   for(int i = 0; i < n; i++) {
      cout<<"Enter Element "<<(i+1)<< ": ";
      cin>>num[i];
   }
   // Storing first array element in "largest" variable
   largest = num[0];
   for(int i = 1;i < n; i++) {
      /* We are comparing largest variable with every element
       * of array. If there is an element which is greater than
       * largest variable value then we are copying that variable
       * to largest, this way we have the largest element copied
       * to the variable named "largest" at the end of the loop 
       *
       */
      if(largest < num[i])
         largest = num[i];
   } 
   cout<<"Largest element in array is: "<<largest;
   return 0;
}

Example 2: how to set an integer equal to the largest integer possible in c++

// largest int in c++
signed int iMax = (unsigned int)~0 >> 1;
// largest unsigned int
unsigned int uMax = (unsigned int)~0;