Question

我一直在努力获取代码，以便按升序然后降序排列3个数字。但是，代码会跳过if语句并假定数字是有序的。这是我第一次在C中使用if语句和第二天学习指针，所以任何帮助都会受到赞赏。谢谢

#include<stdio.h>
void swap(int *, int *, int *);
int main(void){

printf("Please enter the first number to sort: ");
scanf("%d",&numberOne);

printf("Please enter the second number to sort: ");
scanf("%d",&numberTwo);

printf("Please enter the third number to sort: ");
scanf("%d",&numberThree);

//swap

swap(&numberOne, &numberTwo, &numberThree);

//return results

printf("The three numbers in descending order is: %d, %d, %d", 
numberOne, numberTwo, numberThree);

printf("THe three numbers in ascending order is: %d, %d, %d", 
numberThree, numberTwo, numberOne);
}

void swap(int *numberOne, int *numberTwo, int *numberThree){
if (numberOne>numberTwo){
if (numberTwo<numberThree){
int temp =*numberTwo;
*numberTwo=*numberThree;
*numberThree = temp; }
// "312"

else if (numberTwo>numberOne){
    if (numberOne>numberThree){
    int temp =*numberOne;
    *numberOne =*numberTwo;
    *numberTwo= temp;
    // "231"
}
    else if(numberOne<numberThree){
    if(numberTwo>numberThree){
    int temp =*numberOne;
    *numberOne =*numberTwo;
    *numberTwo =*numberThree;
    *numberThree = temp;
    // "132"
    }
    }
}
else if (numberThree > numberOne){
    if (numberTwo< numberOne){
    int temp =*numberThree;
    *numberThree =*numberTwo;
    *numberTwo =*numberOne;
    *numberOne = temp;
    // "213"
}
else {
    int temp = *numberThree;
    *numberThree = *numberOne;
    *numberOne = temp;
    // "123"
    }
}

}
else{
printf("Look at that these numbers were in order...");
}
}

Answer 1

执行此操作时：if (numberTwo>numberOne)，您正在比较指针。而且你需要比较这些指针背后的值。所以：if (*numberTwo>*numberOne)

Answer 2

这会有用吗？！ BTW！ “大整数”和“小整数”的定义具有其他技术含义。

void swap(int *numberOne, int *numberTwo, int *numberThree){
    int tmp;

    if(*numberOne > *numberThree ){
        tmp             = *numberThree;
        *numberThree    = *numberOne;
        *numberOne    = tmp;
    }


    if(*numberTwo > *numberThree ){
        tmp             = *numberThree;
        *numberThree    = *numberTwo;
        *numberTwo    = tmp;
    }
    if(*numberOne > *numberTwo ){
        tmp             = *numberTwo;
        *numberTwo    = *numberOne;
        *numberOne    = tmp;
    }


}

C编程，if语句（大到小整数交换）

2 个答案: