我在用 c 语言找到 3 个数字的平均值时遇到问题

Question

i am giving my code down below i want to tell you that i am getting my answer correct at the end but while i am putting the value there is some strange numbers coming left to it and also when i want to put my first value i always have to put the value twice i am just a beginner in c language if you can help me it will be really great thanks for giving your time

  #include<stdio.h>

int main ()
{
int a;
int b;
int c;

printf("please enter 3 numbers ");

printf("Enter 1st Number %d ", a);
scanf("%d ", &a);

printf("Enter 2nd Number %d ",  b);
scanf("%d ", &b);

printf("Enter 3rd Number %d ", c);
scanf("%d ", &c);

printf("Now you can see average of the three numbers \n");

int d = a + b + c ;
int e = d/3;

printf("%d ", e);

return 0;

}

Answer 1

In your code, you are prompting the user for the entry of a number using the "printf()" function which is good. However, there is no need to include the variable in the "printf()" statements as the values will be entered into your integer variables with the associated "scanf()" functions.

What is happening here is that when you defined your three integers (a, b, and c), you allocated memory space for those integer variables. And since those variables are not initialized with a value, the contents of those integers will contain whatever data value happens to be left over in that integer's memory location.

Simply, what you can do is change your prompt statement from:

printf("Enter 1st Number %d ", a);
scanf("%d ", &a);

printf("Enter 2nd Number %d ",  b);
scanf("%d ", &b);

printf("Enter 3rd Number %d ", c);
scanf("%d ", &c);

to:

printf("Enter 1st Number: ");
scanf("%d", &a);

printf("Enter 2nd Number: ");
scanf("%d", &b);

printf("Enter 3rd Number: ");    
scanf("%d", &c);

You will notice that I removed the trailing space in the "scanf()" formatting character. That was producing extra spaces.

Hope that clarifies things.

Regards.