How to write a C Program to find the Second largest Number in an Array with example.? Before going into this second largest number example.
C Program to find Second largest Number in an Array
This program for finding the second largest number asks the user to enter the Array size, Array elements, and the Search item value. Next, this program will find the Second largest Number in this Array using For Loop.
#include <stdio.h>
#include <limits.h>
int main()
{
int arr[50], i, Size;
int first, second;
printf("\n Please Enter the Number of elements in an array : ");
scanf("%d", &Size);
printf("\n Please Enter %d elements of an Array \n", Size);
for (i = 0; i < Size; i++)
{
scanf("%d", &arr[i]);
}
first = second = INT_MIN;
for (i = 0; i < Size; i++)
{
if(arr[i] > first)
{
second = first;
first = arr[i];
}
else if(arr[i] > second && arr[i] < first)
{
second = arr[i];
}
}
printf("\n The Largest Number in this Array = %d", first);
printf("\n The Second Largest Number in this Array = %d", second);
return 0;
}
In this C Program to find the second largest number in an array, We declared 1 One Dimensional Arrays arr[] of size 10 and also declared i to iterate the Array elements. Please refer to the Array in C article.
The below statements will ask the user to enter the array arr[] size (Number of elements an Array can hold), and assign the user entered values to the Size variable.
printf("\n Please Enter the size of an array \n");
scanf("%d",&Size);
Below For loop will help to iterate each cell present in a[5] array. Condition inside the for loops (i < Size) will ensure the compiler, not to exceed the array limit.
The C Programming scanf statement inside the for loop stores the user entered values into individual array elements such as arr[0], arr[1], arr[2], arr[3], arr[4]
for(i = 0; i < Size; i++)
{
scanf("%d",&arr[i]);
}
In the next line, We have one more for loop, used to iterate each element in an array. The If Statement inside the For loop will check whether arr[i] is equal to the search item or not. If it is true, then Flag will become 1 and exit from the Loop (using Break Statement)
for (i = 0; i < Size; i++)
{
if(arr[i] > first)
{
second = first;
first = arr[i];
}
else if(arr[i] > second && arr[i] < first)
{
second = arr[i];
}
}
From the above screenshot, you can observe that the user inserted values for the second largest number are
a[5] = {10, 90, 80, 90, 80}
First Iteration: for (i = 0; 0 < 5; 0++)
The value of i will be 0, and the condition (i < 5) is True. So, the program will start executing the statements inside the loop until the condition fails.
If (arr[i] > Search) => if(10 > Int_Min) – Condition is True
second = Int_Min
first = 10
Second Iteration: for (i = 1; 1 < 5; 1++)
The condition (1 < 5) is True.
If (arr[i] > Search) => if(90 > 10) – Condition is True
second = 10
first = 90
Third Iteration: for (i = 2; 2 < 5; 2++) – The condition (2 < 5) is True.
If (arr[i] > Search) => if(80 > 90) – Condition is false. So, it will enter into the Else If block.
else if(arr[i] > second && arr[i] < first)
=> else if(80 > 10 && 80 < 90) – Condition is True
second = arr[i] = 80
Fourth Iteration: for (i = 3; 3 < 5; 3++) – The condition (3 < 5) is True.
If (arr[i] > Search) => if(90 > 90) – Condition is false. So, it will enter into the Else If block.
else if(arr[i] > second && arr[i] < first) => else if(90 > 80 && 90 < 90)
Condition is False
Fifth Iteration: for (i = 4; 4 < 5; 4++) – The condition (4 < 5) is True.
If (arr[i] > Search) => if(80 > 90) – Condition is false. So, it will enter into Else If block.
else if(arr[i] > second && arr[i] < first) => else if(80 > 80 && 80 < 90) – Condition is False
Sixth Iteration: for (i = 5; 5 < 5; 5++)
The condition (4 < 5) is False. So, it will exit from the For Loop
Let me try different array elements for the C Program to find Second largest Number in an Array.
Please Enter the Number of elements in an array : 10
Please Enter 10 elements of an Array
10 10 10 10 10 -5 -5 -2 10 10
The Largest Number in this Array = 10
The Second Largest Number in this Array = -2