Question 1000: Input two integers a and b, calculate the sum of a+b, this question is multiple sets of test data

C language learning website:https://www.docpp.com/course/5

C language:

#include /*Introduce header files*/int main(void) /* a simple C program */{int number; /*define a variable named number*/number=2014; /*Assign a value to number*/printf("Hello ! I am dotcpp.com\n"); /*call printf() function*/printf("This year is %d\n",number);return 0;}

Question 1: Input two integers a and b, calculate the sum of a+b

Note that this question is multiple sets of test data, that is, you need to continuously receive the test input of the system, you can calculate the result and output it

Method 1:

#include int main(){int a,b; //Define two variables a,b, the type is integerwhile(~scanf("%d%d",&a,&b)) //Continue to loop if non-zeroprintf("%d\n",a+b); //Enter the loop statement, if a and b are given a value, output a+b; %d replaces the unknown integerreturn 0; //return value}

Display of running results:

Solution ideas:

Function name: scanf

Function: Execute formatted input

Usage: int scanf(char *format[...,argurment,....]);

The scanf() function uses a generic terminal formatted input function to read input information from the standard input device (keyboard).Can read in any inherent type of data and automatically convert the value to the appropriate on-board format.

The calling format is: scanf("",

);

Analysis of the role of ~:

1. Under Windows, if the user presses CTRL+Z (you will see a ^Z character), the input stream will be stopped, and scanf will return -1.

The complement of 2 and -1 is 11111111 11111111 11111111 11111111 a total of 4 bytes.

3, ~ is the bitwise inversion in C language, so the result of ~(-1) is 00000000 00000000 00000000 00000000 is exactly the complement of integer 0.

4. Therefore, when Ctrl+Z is input, scanf will return -1, while(~-1)==while(0), 0 is false, and exit the while loop.

Method 2:

#includeint main(){int a,b;while(scanf("%d%d", &a, &b)==2)//When ==2, that is, the case where the scanf() function returns a value of 1 (see below)printf("%d\n",a+b);return 0;}

[Note] The return value of the scanf function is the key point and must be understood.

The return value of the scanf() function is divided into three types:

(1) returns a positive integer.Indicates the number of correct input parameters.

(2) returns the integer 0.Indicates that the user's input did not match and no value could be entered correctly.

(3) returns -1.Indicates that the input stream has ended.Under Windows, the user presses CTRL+Z (you will see a ^Z character) and then presses Enter (which may need to be repeated several times), which means the end of the input; under Linux/Unix, use CTRL+D to indicate the end of the input.

Java:

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);while (scanner.hasNext()) {int a = scanner.nextInt();int b = scanner.nextInt();int c = a + b;System.out.println(c);}}}