c - 随机字符数组排序

Question

我在编译程序时遇到问题，并且不确定我的逻辑和/或语法是否正确。我想做的是创建一个大小(由用户定义)的字符串数组，每个字符串 20 个字符。

//Melissa P. 
//University of Massachusetts Dartmouth
//CIS362
//2-6-2016

#include <stdio.h>

#define MIN 0 //For the random number generator
#define MAX 51 //so it can properly choose randomly a letter from my given array in getRandomString function

int getNum(void);
char * getRandomString(void);

int main (void)
{
    int input = 0;
    int i = 0;
    int j = 0;
    char word[20]; //placeholder for the random string result


    printf("How many strings do you want in the array? "); //questions the user for amount of 20 character strings
    scanf("%d", &input); 
    const char *array[input]; //pointer array of size defined by user

    for (i = 0; i < input; i++)
    {
        *word = getRandomString(); //gets the 20 character string from the function
        array[i] = *word; //and puts it in each space of the array
    }

    for (i = 0; i < input; i++)
    {
        printf("%s\n", array[i]); //prints the array
    }

}

int getNum() //function to get a random number between 0 and 51.
{
    int num;
    num = rand()% ((MAX + 1) - MIN) + MIN;
    return num;
}

char * getRandomString(void)
{
    char word[20]; //declares the array for the random word to go in.
    int num = 0;
    int i = 0;
    char letterArray[52] = {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 
                      'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 
                      'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 
                      'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 
                      'W', 'X', 'Y', 'Z'}; //array of all lower case and upper case letters

    for (i = 0; i < 20; i++)
    {
        num = getNum(); //gets a random number seed
        word[i] = letterArray[num]; //fills the word array with a random letter
    }
    word[i] = '\0';

    return *word; //returns the string
}

我得到的错误是这样的:“赋值从指针生成整数而不进行强制转换”这发生在 main 和 getRandomString 方法中。谢谢!

Answer 1

您的代码有很多错误，我已纠正您的错误，请尝试:

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

#define MIN 0 //For the random number generator
#define MAX 51 //so it can properly choose randomly a letter from my given array in getRandomString function

int getNum(void);
char * getRandomString(void);

int main (void)
{
    int input = 0;
    int i = 0;
    int j = 0;
    char* word; //placeholder for the random string result


    printf("How many strings do you want in the array? "); //questions the user for amount of 20 character strings
    scanf("%d", &input); 
    char **array = malloc(input * sizeof(char*)); //pointer array of size defined by user

    for (i = 0; i < input; i++)
    {
        array[i] = malloc(21);
    }

    for (i = 0; i < input; i++)
    {
        word = getRandomString(); //gets the 20 character string from the function
        strcpy(array[i],word); //and puts it in each space of the array
        free(word);
    }

    for (i = 0; i < input; i++)
    {
        printf("%s\n", array[i]); //prints the array
    }

    //free memory
    for (i = 0; i < input; i++)
    {
        free(array[i]);
    }

    free(array);
}

int getNum() //function to get a random number between 0 and 51.
{
    int num;
    num = rand()% ((MAX + 1) - MIN) + MIN;
    return num;
}

char * getRandomString(void)
{
    char* word = malloc(21); //declares the array for the random word to go in.
    int num = 0;
    int i = 0;
    char letterArray[52] = {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 
                      'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 
                      'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 
                      'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 
                      'W', 'X', 'Y', 'Z'}; //array of all lower case and upper case letters

    for (i = 0; i < 20; i++)
    {
        num = getNum(); //gets a random number seed
        word[i] = letterArray[num]; //fills the word array with a random letter
    }
    word[i] = '\0';

    return word; //returns the string
}

你必须研究更好的指针，你必须使用 string.h 作为 strcpy 函数，使用 stdlib.h 作为 malloc。