c - 调试 C 代码

Question

有人可以告诉我我的代码有什么问题以及为什么会产生此输出。

代码:

int main(){
  unsigned num;
  char response;

do{
 printf("Please enter a positive integer greater than 1 and less than 2000: ");
 scanf("%d", &num);
 if (num > 1 && num < 2000){
    printf("All the prime factors of %d are given below: \n", num);
    printPrimeFactors(num);
    printf("\n\nThe distinct prime factors of %d are given below: \n", num);
    printDistinctPrimeFactors(num);
 }
 else{
    printf("\nSorry that number does not fall between 1 and 2000.\n");
 }
 printf("\n\nDo you want to try another number? Say Y(es) or N(o): ");
 getchar();
 response = getchar();
}
while(response == 'Y' || response == 'y'); // if response is Y or y then program runs again
printf("Thank you for using my program. Good Bye!\n\n"); //if not Y or y, program terminates
return 0;
}

输出:

Please enter a positive integer greater than 1 and less than 2000: 1600
All the prime factors of 1600 are given below: 
2 2 2 2 2 2 5 5 

The distinct prime factors of 1600 are given below: 
2 5 

Do you want to try another number? Say Y(es) or N(o): yes
Please enter a positive integer greater than 1 and less than 2000: All the prime factors of 1600 are given below: 
2 2 2 2 2 2 5 5 

The distinct prime factors of 1600 are given below: 
2 5 

Do you want to try another number? Say Y(es) or N(o): Thank you for using my program. Good     Bye!

Answer 1

当您询问是否要重复时，您只读取y，而将es留在标准输入中排队。当您读取下一个数字时，scanf 尝试将其解析为数字，失败并返回而不更改 num。当您提示用户时，您需要烧掉整行。