Difference between structured and unstructured programming

// C program to demonstrate the
// structured programming
#include <stdio.h>

// Function for addition
int sum(int a, int b)
{
    return a + b;
}

// Function for Subtraction
int sub(int a, int b)
{
    return a - b;
}

// Driver Code
int main()
{
    // Variable initialisation
    int a = 10, b = 5;

    int add, minus;

    // Function Call
    add = sum(a, b);
    minus = sub(a, b);

    printf("Addition = %d\n", add);
    printf("Subtraction = %d\n", minus);
    return 0;
}

// C program to demonstrate the
// unstructured programming

#include <stdio.h>

// Driver Code
int main()
{
    // Variable initialisation
    int a = 10, b = 5;
    int add, minus;

    // Operations performed
    add = a + b;
    minus = a - b;

    printf("Addition = %d\n", add);
    printf("Subtraction = %d\n", minus);
    return 0;
}