Step by Step solution about How to resolve the algorithm A+B step by step in the C programming language

1. Standard Input-Output Streams:

#include <stdio.h>

int main() {
   int a, b;
   scanf("%d%d", &a, &b);  // Reads integers from standard input
   printf("%d\n", a + b);  // Prints the sum to standard output
   return 0;
}

• This C program reads two integers a and b from the standard input (usually the keyboard) using scanf, performs the sum, and writes the result to the standard output (usually the console) using printf.

2. Redirecting Input and Output:

#include <stdio.h>

int main() {
   freopen("input.txt", "rt", stdin);  // Redirects input from file "input.txt"
   freopen("output.txt", "wt", stdout);  // Redirects output to file "output.txt"
   int a, b;
   scanf("%d%d", &a, &b);
   printf("%d\n", a + b);
   return 0;
}

• This program reads input from a file named "input.txt" and writes output to a file named "output.txt" by using freopen to redirect stdin (standard input) and stdout (standard output).

3. Parsing Command-Line Arguments:

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char **argv) {  // argc contains the number of arguments, argv contains the arguments themselves
   printf("%d\n", atoi(*(argv+1)) + atoi(*(argv+2)));  // Converts the second and third arguments to integers and adds them
   return 0;
}

• This program takes command-line arguments and uses atoi to convert the arguments to integers. The second and third arguments are summed and printed to the standard output.

// Standard input-output streams
#include <stdio.h>
int main()
{
   int a, b;
   scanf("%d%d", &a, &b);
   printf("%d\n", a + b);
   return 0;
}


// Input file: input.txt
// Output file: output.txt
#include <stdio.h>
int main()
{
   freopen("input.txt", "rt", stdin);
   freopen("output.txt", "wt", stdout);
   int a, b;
   scanf("%d%d", &a, &b);
   printf("%d\n", a + b);
   return 0;
}


#include <stdio.h>
#include <stdlib.h>
int main(int argc, char **argv) //not sure if argv counts as input stream... certainly it is brought here via input stream.
{
   printf("%d\n", atoi(*(argv+1)) + atoi(*(argv+2)));
   return 0;
}