重新分配存储器并在C中的重新分配存储器空间增加一个串 [英] Reallocating memory and adding a string at the reallocated memory space in C

问题描述

我无法加入记录在动态分配的字符串数组的结尾。重新分配更多的内存要添加的记录之前，一切工作正常，然后我基本上复制了我最初没有，但现在的realloc。而我做的输入添加的记录后，我得到一个错误，我不知道如何去添加记录。注：*本带来code是真的从原来的剥离下来。我尝试过很多事情，但不得要领，感谢所有帮助提前。

 的#include＆LT;＆stdio.h中GT;
＃包括LT＆;＆stdlib.h中GT;
＃定义stringsize的21无效addRecords（字符**名称，INT classSize）;诠释主（）{
    焦炭**名称;
    INT classSize，我;    //用户将能够选择他多少条记录woudld喜欢的输入。
    的printf（请说明你要输入的记录数：\\ n）;
    scanf函数（％d个，＆安培; classSize）;    名称=的malloc（classSize * sizeof的（字符*））;    对于（i = 0; I＆LT; classSize;我++）{
        名称[I] =的malloc（stringsize的*的sizeof（字符））;
    }
    的printf（请学生输入记录（输入每条记录后，新行），具有以下格式：第一个名字.... \\ n）;    对于（i = 0; I＆LT; classSize;我++）{
        scanf函数（％S，*（姓名+ I））;
    }    对于（i = 0; I＆LT; classSize;我++）{
        的printf（％S，*（姓名+ I））;
        的printf（\\ n \\ n）;
    }addRecords（名称，classSize）;
}无效addRecords（字符**名称，诠释classSize）{
    INT另外，我;    的printf（你会如何对多条记录想补充\\ n吗？）;
    scanf函数（％d个，＆安培;另外）;    名称=的realloc（名称，（classSize +加）* sizeof的（字符*））;    对于（i = classSize;我≤（classSize +加）;我++）{
        名称[I] =的malloc（stringsize的*的sizeof（字符））;
    }    的printf（请学生输入记录（输入每条记录后，新行），与followingformat：名字.... \\ n）;    对于（i = classSize; I＆LT; classSize +另外，我++）{
        scanf函数（％S，*（姓名+（classSize + I）））;
    }
    的printf（\\ n \\ n）;
    对于（i = 0; I＆LT; classSize +另外，我++）{
        的printf（％S，*（姓名+ I））;
    }    的printf（\\ n \\ n）;
}
 

解决方案

您正在编写出数组的边界的：

 为（I = classSize; I＆LT; classSize +另外，我++）{
    scanf函数（％S，*（姓名+（classSize + I）））;
 

更改

 为（I = classSize; I＆LT; classSize +另外，我++）{
    scanf函数（％S，*（姓名+ I））;
 

注意名称[I] 比 *（姓名+ I）

更具可读性

I am having trouble adding "records" at the end of a dynamically allocated string array. Before reallocating more memory for the records to be added, everything works fine, and then I basically replicate what I initially did but now with realloc. And after I am done inputting the added Records I get an error and I don't know how to go about adding records. NOTE* The posed code is really stripped down from the original. I've tried many things but to no avail, thanks for all the help in advance.

#include <stdio.h>
#include <stdlib.h>
#define STRINGSIZE 21

void addRecords( char **Names, int classSize);

int main(){
    char **Names;
    int classSize, i;

    //User will be able to choose how many records he woudld like to input.
    printf("Please indicate number of records you want to enter:\n");
    scanf("%d", &classSize);

    Names=malloc(classSize*sizeof(char*));

    for (i=0; i<classSize; i++) {
        Names[i]=malloc(STRINGSIZE*sizeof(char));
    }
    printf("Please input records of students (enter a new line after each record), with following format: first name....\n");

    for (i=0; i<classSize; i++) {
        scanf("%s", *(Names + i));
    }

    for (i=0; i<classSize; i++) {
        printf("%s ", *(Names+i));                
        printf("\n\n");
    }

addRecords(Names, classSize);
}

void addRecords(char **Names, int classSize){
    int addition, i;

    printf("How many records would you like to add?\n");
    scanf("%d", &addition);

    Names=realloc(Names, (classSize+addition)*sizeof(char*));

    for (i=classSize; i<(classSize+addition); i++) {
        Names[i]=malloc(STRINGSIZE*sizeof(char));
    }

    printf("Please input records of students (enter a new line after each record), with followingformat: first name....\n");

    for (i=classSize; i<classSize+addition; i++) {
        scanf("%s", *(Names + (classSize + i)));
    }
    printf("\n\n");
    for (i=0; i<classSize+addition; i++) {
        printf("%s ", *(Names+i));
    }

    printf("\n\n");
}

解决方案

You are writing out of the bounds of the array:

for (i=classSize; i<classSize+addition; i++) {
    scanf("%s", *(Names + (classSize + i)));

change to

for (i=classSize; i<classSize+addition; i++) {
    scanf("%s", *(Names + i));

Note that Names[i] is more readable than *(Names + i)

这篇关于重新分配存储器并在C中的重新分配存储器空间增加一个串的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！