将4位整数除以2位整数并用c计算

Question

//Enter a 4-digit integer n from the keyboard, and write a program to divide it into two 2-digit integers a and B. Calculate and output the results of the addition, subtraction, multiplication, division and redundancy operations of the split two numbers. For example, n=-4321, if the two integers after splitting are a and b, then a=-43 and b=-21. The result of division operation requires that it be precise to 2 decimal places, and the data type is float. Redundancy and division operations need to take into account the division of 0, that is, if the split B = 0, then output the prompt information "The second operator is zero!"

//Failure to pass the test，how should i fix

#include<stdio.h>
#include<math.h>

int main()
{
    int x, a, b;
    printf("Please input n:\n");
    scanf("%d", &x);
    a = x / 100;
    b = x % 100;
    printf("%d,%d\n", a, b);
    printf("sum=%d,sub=%d,multi=%d\n", a + b, a - b, a*b);
    if (b == 0)
        printf("The second operater is zero!");
    else
        printf("dev=%.2f,mod=%d\n", (float)a / b, a%b);
}

Answer 1

You forgot to check that x is a 4-digits number. So if the input is 12345 or 123 you don't satisfy the requirement.

#include <stdio.h>

int main()
{

    int x, a, b;
    int passed = 0;

    // Enter a 4 digits number: ABCD
    do {
        printf("Enter X = ");
        scanf("%d", &x);
        passed = (x >= 1000 && x <= 9999) || (x >= -9999 && x <= -1000);
    } while (!passed);

    a = x / 100;
    b = x % 100;

    printf("Numbers: %d %d \n", a, b);

    printf("Sum = %d \n", a + b);
    printf("Sub = %d \n", a - b);
    printf("Mul = %d \n", a * b);
    if (0 == b) {
        printf("Div by Zero \n");    
    } else {
        printf("Div = %f \n", (double)a / b);
        printf("Mod = %d \n", a % b);
    }

    return 0;
}