c - 当我执行程序时，它关闭

Question

当我执行程序时，它会关闭。编译完成后，程序窗口打开，然后我可以输入客户端的ID，之后，它卡住，然后一个新的弹出窗口说程序已停止工作，需要关闭。我已将问题隔离到这一行，first = middle + 1;任何帮助将非常感激。该程序构建为在 Dev C++ 上以 C 语言运行。

#include <stdio.h>
#include <string.h>
typedef struct//Declares structure to hold seven created datatypes.
{
    int client_id;
    char client_business_name [30];
    char client_first_name [20];
    char client_last_name [20];
    char client_address [40];
    float client_budget;
    char client_business_info [300];
}Client;

main()
{
    Client c[100];
    int y;
    printf ("\nEnter Client ID:");
    scanf ("%d",&c[y].client_id);
    printf ("Enter Buisness Name:");
    scanf (" %[^\n]",c[y].client_business_name);
    printf ("Enter Client First Name:");
    scanf (" %[^\n]",c[y].client_first_name);     
    printf ("Enter Client Last Name:");
    scanf (" %[^\n]",c[y].client_last_name);     
    printf ("Enter Buisness Address:");
    scanf (" %[^\n]",c[y].client_address);
    printf ("Enter Client Budget:");
    scanf ("%f",&c[y].client_budget);
    printf ("Enter Buisness Information:");
    scanf (" %[^\n]",c[y].client_business_info);

    printf ("ID:%d\n",c[y].client_id);

    int key,max=100;
    printf ("\nEnter Client ID To Be Deleted:");
    scanf ("%d",&key);
    system ("cls");
    int first = 0;
    int last = max - 1;
    int middle = (first+last)/2;
    while( first <= last )
    {
        if (c[middle].client_id < key)
            first = middle + 1;    
        else if (c[middle].client_id == key) 
        { 
            c[middle].client_id=c[middle+1].client_id;
            strcpy(c[middle].client_business_name,c[middle+1].client_business_name);
            strcpy(c[middle].client_first_name,c[middle+1].client_first_name);
            strcpy(c[middle].client_last_name,c[middle+1].client_last_name);
            strcpy(c[middle].client_address,c[middle+1].client_address);
            c[middle].client_budget=c[middle+1].client_budget;
            strcpy(c[middle].client_business_info,c[middle+1].client_business_info);                     
            printf ("\nClient Removed!");  
            break;
        }
        else
            last = middle - 1;
        middle = (first + last)/2;
    }
    if ( first > last )
    {
        printf ("\nClient Not Registered\n");
    }
    system ("PAUSE");
}  

Answer 1

 while( first <= last )
 {
    if (c[middle].client_id < key)
       first = middle + 1;  
    else if (c[middle].client_id == key) 

您不会重新计算 if 子句中的中间值。因此，如果您输入该子句，您将首先设置 middle + 1，然后您将再次旋转循环，并且 middle 是相同的值。所以你会一次又一次地这样做，这就是你被吊死的原因。该子句不会推进您的循环。尝试像在 else 子句中那样更新 middle 。