Optimizing a C Program for Summing Odd and Even Numbers: A Comprehensive Guide

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In this article, we will explore and optimize a C program designed to calculate the sum of odd and even numbers within a given range. The program is compatible with Microsoft QuickC Version 2.00, and we will discuss both version 1 and an improved version 2. We will also cover the logic and performance optimizations utilized in the code.

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Version 1 Overview

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Version 1 of the program works by taking user input for an integer, then proceeds to calculate the sum of odd and even numbers within a given range.

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include stdio.hint main(void) {    register int i  00;    signed char nline  00;    signed char sign[2][9]  {        '0'    };    signed int index  00;    signed long int num  00L;    signed long int o_sum  00L;    signed long int e_sum  00L;    // Show the program's purpose to the user.    printf("
Enter an integer as the ending point: ");    printf("
This program will calculate the sum of odd and even integers from 0 to the given number.
");    // User input.    printf("
Enter the ending integer: ");    scanf("%ld", num);    fflush(stdin);    // Check and sum.    if (num > 0) {        // Positive number        while (i 

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Optimizations and Improvements in Version 2

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Version 2 of the program introduces several optimizations and improvements. One of the primary changes is the use of bitwise operators to check if a number is odd or even, which enhances performance. Additionally, the program handles negative numbers more accurately and efficiently.

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include stdio.hint main(void) {    signed char nline  00;    signed char sign[2][9]  {        '0'    };    signed int index  00;    signed long int i  00L;    signed long int num  00L;    signed long int o_sum  00L;    signed long int e_sum  00L;    // Show the program's purpose to the user.    printf("
Enter an integer as the ending point: ");    printf("
This program will calculate the sum of odd and even integers from 0 to the given number.
");    // User input.    printf("
Enter the ending integer: ");    scanf("%ld", num);    fflush(stdin);    // Check and sum.    if (num > 0) {        if (num  01) {            // num is ODD            o_sum  01L   num   01L * num / 04L;            e_sum  num - 01L   01L * num / 04L;        } else {            // num is EVEN            o_sum  num   num / 04L;            e_sum  num   02L * num / 04L;        }    } else if (num 

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Example Outputs

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Here are example outputs for both versions of the program:

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Example Output for Version 1

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Enter the ending integer: 20The sum of positive odd integers from 0 to 20 is: 100The sum of positive even integers from 0 to 20 is: 110Program complete.

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Example Output for Version 2

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Enter the ending integer: 20The sum of positive odd integers from 0 to 20 is: 100The sum of positive even integers from 0 to 20 is: 110Program complete.

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Note: The output for both versions is identical to the original example, as the optimizations do not alter the core functionality.

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Conclusion

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The provided C program is a practical example of how to implement and optimize algorithms for summing odd and even numbers. Version 2 showcases significant improvements in terms of performance and handling of edge cases, such as negative numbers. By leveraging bitwise operations and proper logic, the program can efficiently handle a wide range of inputs and produce accurate results.

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For further reading and learning, you may want to explore additional topics in C programming, such as bitwise operations, user input handling, and performance optimization techniques.