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Question

我是c编程的初学者。所以我可能不知道很多东西。但有人能告诉我为什么我的代码在最后一行完成后会崩溃吗？它可能是我定义的数组吗？

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


void main()
{

unsigned int totSession, totStudent;
int x, y, i, j;
int *studID,*con,*k;
char (*name1)[40];
int *frequency;

printf("Enter number of consultation\n"); //input number of consultation
scanf("%d", &totSession);
printf("Enter number of students\n"); //input number of students
scanf("%d", &totStudent);

studID = (int *)malloc(totStudent * sizeof(int));
con = (int *)malloc(totStudent * sizeof(int)); 
name1 = (char *)malloc(totStudent * sizeof(char));
frequency = (int *)malloc(totStudent * sizeof(int));
k = (int *)malloc(totSession * sizeof(int));

for (x = 0; x < totStudent; ++x) //Entering each students details
{
    printf("Enter details of Student[%d]\n", x + 1);
    printf("Enter StudentID:");
    scanf("%d", &studID[x]);
    printf("Enter student's Full name:");
    scanf("%s", &name1[x]);
    printf("Which consultation to choose for student:");
    scanf("%d", &con[x]);
}

printf("%s%15s%40s\n", "Student ID", "Fullname", "Which consultation session to choose");

for (y = 0; y < totStudent; ++y) //print all student details
{
    printf("%-17d%-23s%d\n\n", studID[y],name1[y],con[y]);
}


for (i = 0; i <= totStudent; ++i) //set all arrays of frequency to 0
{
    frequency[i]=0;
    k[i] = 0;
}

for (i = 0; i < totStudent; ++i) //summarise consultation
{
    ++frequency[con[i]];
    k[i + 1] += (i+1);           //create constant for session number
}

if (totStudent > 1)
{
    int hold, hold1;
    for (i = 0; i < totSession; ++i) //sorting
    {
        for (j = 1; j <= (totSession - 1); ++j)
        {

            if (frequency[j] < frequency[j + 1])
            {
                hold = frequency[j];
                hold1 = k[j];
                frequency[j] = frequency[j + 1];
                k[j] = k[j + 1];
                frequency[j + 1] = hold;
                k[j + 1] = hold1;
            }
        }
    }
}
printf("%s%50s", "Consultation Session Number", "The number of students choose this session\n");

for (i = 1; i <= totSession; ++i)
{
    printf("%10d%40d\n",k[i], frequency[i]);
}
printf("The session to offer is: Session %d with %d (out of %d) students chosen.\n", k[1], frequency[1], totStudent);


getch();
}

任何帮助将不胜感激！在代码的末尾已经完成了free（），但它也不起作用..

Answer 1

如果＆＃34;崩溃＆＃34;你的意思是它无法编译源代码时出现以下错误：

/tmp/ccvGANfB.o: In function `main':
tmp.c:(.text+0x4d2): undefined reference to `getch'
collect2: error: ld returned 1 exit status

它是因为你试图使用一个不存在的函数（getch）（公平地说它存在于curses库中，但我非常怀疑你的意思是什么）使用）。你可能错过了getchar（）。

简而言之，在最后一行代替

 getch();

与

 getchar();

PS：＆＃34;崩溃＆＃34;一个通常是指运行时错误（程序在执行时失败;程序无法编译，它会抛出编译时错误。