為什么這個程序在第一次 scanf 之后進入無限循環？

Question

我試圖讓程序允許用戶輸入一個數字，然后讓計算機告訴用戶這個數字是太小、太大還是等於隨機生成的數字。 提示和輸入工作，但它在第一次 scanf 后卡住了。

我認為它與 scanf 而不是條件有關，因為我添加了 printf("Testing stop point") 並且不會打印到用戶的屏幕上。 我究竟做錯了什么？

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

int main()
{
        //Generate a random number
        int n = 1;
        int count = 0;
        int randomNumber;
        srand(time(NULL));

        for (int i = 1; i <= n; i++)
        {
                randomNumber = rand() % 101;
        }

        printf("Guess a number between 1 - 100: ");

        int input;
        scanf("%d\n",&input);

        printf("Testing stopping point");

        do
        {
            if (input > randomNumber)
            {
                count +=1;
                printf("Too large!Try again: ");
                getchar();
            }else if (input < randomNumber)
            {
                count += 1;
                printf("Too small!Try again: ");
                getchar();
            }
        }while (input != randomNumber);

        if(input == randomNumber)
        {
            count +=1;
            printf("Correct!\n");
            printf("You guessed %d times\n", count);
            return 0;
        }
}

Answer 1

您必須刪除scanf中的\n ，嘗試如下：

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

int main()
{
        //Generate a random number
        
        int count = 0;
        int randomNumber;
        srand(time(NULL));
        randomNumber = (rand() % 101)+1;
        int input=-1;
      
        while (input != randomNumber)
        {
              printf("Guess a number between 1 - 100: ");
             scanf("%d",&input);
            if (input > randomNumber)
            {
                count +=1;
                printf("Too large!Try again: ");
                
            }else if (input < randomNumber)
            {
                count += 1;
                printf("Too small!Try again: ");
               
            }
         
        }
if(input == randomNumber)
        {
            count +=1;
            printf("Correct!\n");
            printf("You guessed %d times\n", count);
           
        }

       return 0; 
}