我的程序有问题。我用一个虚拟的 alfabeth 制作了一个简单的编码程序,但是在尝试访问 char 数组时它无法访问该位置,怎么会?我不知道它是否与 size_t 类型而不是 int 类型有关?
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include <ctype.h>
static char * createAlfa(void);
char * codify(char *mess, char *alfa);
int
main(void)
{
char *alfa=createAlfa();
printf("write your mess to codify: \n");
char mess[]="";
scanf("%s", mess);
char *code=codify(mess, alfa);
printf("your codified message is: %s\n", code);
return 0;
}
static char *
createAlfa(void)
{
char *codealfa=malloc(sizeof(char)*27);
srand((unsigned int)time(NULL));
int i, ran;
for(i=0; i<26; i++)
{
codealfa[i]='A'+i;
if((ran=rand()%26)<i)
{
codealfa[i]=codealfa[ran];
codealfa[ran]='A'+i;
}
}
codealfa[26]=0;
return codealfa;
}
char *
codify(char *mess, char *alfa)
{
size_t len=strlen(mess);
char *code=malloc(sizeof(char)*len);
int i;
for(i=0; i<len; i++)
{
int pos=(int)(toupper(mess[i])-'A'); //pos is behaving correctly, first loop is
//it is 15 when i write "potato"
code[i]=alfa[pos]; //EXC_BAD_ACCESS, Could not access memory
}
code[i]=0;
return code;
}