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我正在尝试编写一个程序，该程序采用名称列表，对这些名称进行排序，并允许用户从该列表中搜索名称。程序可以编译，但是一旦用户输入“y”来搜索名称并输入了他想要搜索的名称，程序就会冻结。

我很感激任何帮助！

#include <stdio.h>
#include <stdbool.h>
#include <string.h>

#define NUM_OF_NAMES 8
#define NAME_SIZE 5

void printNames(char names[][NAME_SIZE], int size);
void bubbleSortNames(char names[][NAME_SIZE], int last);
bool binarySearchNames(char list[][NAME_SIZE], int end, char target[], int *location);

int main()
{
    char nameList[NUM_OF_NAMES][NAME_SIZE] = {"Bob", "Sue", "Jake","Rod", "Jon", "Ash", "Deb", "Kay"};
    char searchText[NAME_SIZE];
    char userChoice;
    int searchLocation;

    printf("\n\n\nLIST BEFORE SORTING\n");    
    printNames(nameList, NUM_OF_NAMES);
    bubbleSortNames(nameList, NUM_OF_NAMES);

    printf("\n\n\nLIST AFTER SORTING\n");
    printNames(nameList, NUM_OF_NAMES);

    printf("\n\n\nWould you like to search for a name? (y/n) ");
    scanf(" %s", &userChoice);

    while(userChoice == 'y')
    {
         printf("\n\n\nPlease try to search for a name: ");
         scanf("%s", searchText);

         if(!(binarySearchNames(nameList, NUM_OF_NAMES, searchText, &searchLocation)))
             printf("\n\n\nThe name %s was not found.\n", searchText); 
         else
             printf("\n\n\nThe name %s was found at location %d!", searchText, searchLocation);
    }

    printf("\n\n\nThank you for using this program.\n\n\n");

    return 0;
}

/********************************
Prints the names from the array.
********************************/
void printNames(char names[][NAME_SIZE], int size)
{
    int index;

    for(index = 0; index < size; index++)
        puts(names[index]); 

    return;
}

/*******************************
Sorts the names from the array.
*******************************/
void bubbleSortNames(char names[][NAME_SIZE], int last)
{
    char temp[NAME_SIZE];
    int current;
    int walker;

    for(current = 0; current < last; current++)
    {
        for(walker = last; walker > current; walker--)
        {
            if(strcmp(names[walker], names[walker - 1]) < 0)
            {
                strncpy(temp, names[walker - 1], sizeof(temp) - 1);
                strncpy(names[walker - 1], names[walker], sizeof(names[walker - 1]) -  1);
                strncpy(names[walker], temp, sizeof(names[walker]) - 1);
            }
        }
    }

    return;
}

/*********************************
Searches for names to be printed.
*********************************/
bool binarySearchNames(char list[][NAME_SIZE], int end, char target[], int* location)
{
    int first = 0,
        last,
        mid;

    last = end;   

    while(first <= last);
    {
        mid = (first + last) / 2;

        if(strcmp(target, list[mid]) > 0) 
            first = mid + 1;
        else if(strcmp(target, list[mid]) < 0)
            last = mid - 1;
        else
            first = last +  1;
    }

    *location = mid + 1;

    return (strcmp(target, list[mid]) == 0);
 }
4

2 回答 2

3

在函数 binarySearchNames 中：

while(first <= last) you put a ;

这会导致无限循环。

遇到此类问题时尝试使用调试器。

于 2012-08-13T23:06:49.630 回答
1

scanf("%s", &userChoice);

您是否尝试过删除 %s 之前的空格并将 %s 替换为 %c？两者都可能导致问题。

于 2012-08-13T23:11:21.220 回答