C语言: Write a program that would take 30 integers and prints the largest number and the smallest number

Question

编写一个程序，接受 5 个整数并打印最大数字和最小数字

我尝试了这段代码

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

int main()
{
    int num1, num2, num3, num4, num5;
    int largest;
    int smallest;

    printf ( "\nEnter five integers." );
    printf ( "\nAnd I will give you the smallest and the largest." );

        scanf( "%d%d%d%d%d",  &num1, &num2, &num3, &num4, &num5 );

            if ( num1 >= num2, num3, num4, num5 )
            {
                ( "num1 = largest" );
            }

            if ( num1 <= num2, num3, num4, num5 )
            {
                ( "num1 = smallest" );
            }

            if ( num2 >= num1, num3, num4, num5 )
            {
                ( "num2 = largest" );
            }

            if ( num2 <= num1, num3, num4, num5 )
            {
                ( "num2 = smallest" );
            }

            if ( num3 >= num1, num2, num4, num5 )
            {
                ( "num3 = largest" );
            }

            if ( num3 <= num1, num2, num4, num5 )
            {
                ( "num3 = smallest" );
            }

            if ( num4 >= num1, num2, num3, num5 )
            {
                ( "num4 = largest" );
            }

            if ( num4 <= num1, num2, num3, num5 )
            {
                ( "num4 = smallest" );
            }

            if ( num5 >= num1, num2, num3, num4 )
            {
                ( "num5 = largest" );
            }

            if ( num5 <= num1, num2, num3, num4 )
            {
                ( "num5 = smallest" );
            }

            printf ( "The largest integer is %d.", largest);
            printf ( "The smallest integer is %d.", smallest);

    return 0;
}

但是出了点问题!

请问谁能帮忙解决一下这个问题吗？如果我们可以用 while 循环来做到这一点，请解释一下

谢谢

Answer 1

if ( num1 >= num2, num3, num4, num5 )

这不是比较多个项目的方式。这是有效的 C 代码，但逗号运算符从左到右执行每段代码，并且语句的结果是最后一段的结果。所以你的代码基本上变成:

if (num5)

这不是你想要的。这是比较多个项目的方法:

if ( num1 >= num2 && num1 >= num3 && num1 >= num4 && num1 >= num5 )

另外，

( "num4 = largest" );

确实什么也没做。我想你的意思是

largest = num4;

解决此问题的更可靠方法是首先询问用户他们想要比较多少个数字。这并不限制您只有 5 或 30 个输入。然后，您可以使用 for 循环获取输入，并进行比较:

// How many numbers the user wants to input
int numInput = 0;
printf("How many numbers to compare? ");
scanf(" %d", &numInput);

// Initialize
int largest = INT_MIN;
int smallest = INT_MAX;

int input;

// Loop 
for (int i = 0; i < numInput; i++) {
    // Get next number
    printf("Enter #: ");
    scanf(" %d", &input)) {
    // Compare
    if (input > largest) largest = input;
    if (input < smallest) smallest = input;
}
// Print results
printf("Largest: %d, smallest: %d\r\n", largest, smallest);

注意，需要错误检查。例如:您应该检查 scanf 的返回值以确保您获得了一个数字。