c - 是代码块错误吗？

Question

我有一项作业要求我对随机数进行排序。下面的代码很奇怪。原因是点击运行程序后，如果我在开头输入5，它不能完美运行，但是，它可以与其他数字正常运行。请帮我修复这个错误。我还附上了图片来证明我上面所说的。

Image when enter number 5

Image when enter number 10

#include <stdio.h>
int main(){
int howmany,i,temp,swap;

printf("Enter how many numbers you want to sort: \n");
scanf(" %d",&howmany);

int number[howmany];

printf("*** The original numbers *** \n");

for (i=0;i<howmany-1 ;i++){
    number[i]=(rand()% 25)+1;
    printf("Random number is: %d\n",number[i]);
}

while(1){
    swap = 0;
    for (i=0;i<howmany-1;i++){
        if(number[i]>number[i+1]){
            temp = number[i];
            number[i]=number[i+1];
            number[i+1] = temp;
            swap = 1;
            }

    }
    if (swap == 0){
        break;
    }
}
printf("*** The sorted numbers ***\n");
for (i=0;i<howmany-1;i++){
    printf("The sorted number: %d\n",number[i]);


}


}

Answer 1

问题是因为您正在读取和打印的数据比数组的实际大小小一。因此数组的最后一项将具有一些您不知道的垃圾值。但是在排序时你正在使用它并且它会被排序。有时，垃圾值低于其他随机值，并且会被打印出来。

我已经修复了。请检查所有 for 循环。

#include <stdio.h>
int main(){
int howmany,i,temp,swap;

printf("Enter how many numbers you want to sort: \n");
scanf(" %d",&howmany);

int number[howmany];

printf("*** The original numbers *** \n");

for (i=0;i<howmany ;i++){ //Read howmany values and print
    number[i]=(rand()% 25)+1;
    printf("Random number is: %d\n",number[i]);
}

while(1){
    swap = 0;
    for (i=0;i<howmany-1;i++){
        if(number[i]>number[i+1]){
            temp = number[i];
            number[i]=number[i+1];
            number[i+1] = temp;
            swap = 1;
            }

    }
    if (swap == 0){
        break;
    }
}
printf("*** The sorted numbers ***\n");
for (i=0;i<howmany;i++){ //Print howmany values 
    printf("The sorted number: %d\n",number[i]);


}


}