Question

（已编辑添加此位）我正在编写一个程序，其中读取一串字符，然后计算字符串中每个字母的频率并输出每个字母的次数或非信件。

我正在使用tolower（），但这造成了一个问题。

我已经改变了所以我现在使用循环来降低案例。不幸的是，程序仍在崩溃，我无法发现问题。

我已经完成了每个功能，以确保我没有任何松动。我已经删除了新的线元素但是当我运行它时，我输入了一些简单的“hello”并且它崩溃了。

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


void read(char letterfreq[], int STRSIZE)
{
    printf("The capacity of the string array is %d\n", STRSIZE-1);

    printf("Please enter your string:\n");

    letterfreq[strlen(letterfreq) - 1] = '\0';

    return;
}

void lowerCase(char letterfreq[], int STRSIZE)
{
    }


}

void countFreq(int counter[], int COUNT, char letterfreq[], int STRSIZE)
{
    int c = 0;
    int i;

    for(i = 0; i < STRSIZE; i++)

            }
            else 
                if((letterfreq[i] < 'a') || (letterfreq[i] > 'z'))
                {   
                    counter[COUNT-1]++;
                }
        }
    }

    return;
}

void printFreq(int counter[], int COUNT)
{
    int c;

    printf("Here is the letter frequency of your string:\n");

    for(c = 0; c < COUNT; c++)

    printf("There were also %d special characters in the string.\n", counter[26]);

    return;
}

char promptReset(char reset)
{
    printf("Would you like to calculate the letter frequency of another string? (Y/N)\n");
    scanf("%c%*c", &reset);


    do
    {
        readString(letterfreq, STRSIZE);

        lowerCase(letterfreq, STRSIZE);

        countFreq(counter, COUNT, letterfreq, STRSIZE);

        printFreq(counter, COUNT);

        reset = promptReset(reset);

    }while(reset == 'y' || 'Y');

    return(0);
}

Answer 1

这里（在函数lowerCase中）：

letterfreq[i] = letterfreq[i] - 32;

您需要添加 32才能将字符转换为大写。查看ASCII table以了解原因。

这里（在函数countFreq中）：

for(i = 0; i < STRSIZE; i++)
{   
    while(letterfreq[i] != '\0')
    {   
        if(letterfreq[i] >= 'a' && letterfreq[i] <= 'z')
        {
            counter[c]++;
            c++;
        }
        else 
            if((letterfreq[i] < 'a') || (letterfreq[i] > 'z'))
            {   
                counter[COUNT-1]++;
            }
    }
}

for循环没有任何意义。去掉它。然后，while循环永远不会结束，因为您不会增加i。您需要在i++;循环结束时while。

下面：

        if(letterfreq[i] >= 'a' && letterfreq[i] <= 'z')
        {
            counter[c]++;
            c++;
        }

counter[c]++不计算每个角色的频率。你需要

counter[letterfreq[i]-'a']++;

为此。不需要c。将其从功能中删除。

此外，作为@iharob has mentioned in a comment，

 }while(reset == 'y' || 'Y');

应该是

 }while(reset == 'y' || reset == 'Y');

<小时/> 修正程序：

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

const int COUNT = 27;
const int STRSIZE = 100;

void readString(char letterfreq[], int STRSIZE)
{
    printf("The capacity of the string array is %d\n", STRSIZE-1);

    printf("Please enter your string:\n");
    fgets(letterfreq, STRSIZE, stdin);

    letterfreq[strlen(letterfreq) - 1] = '\0';

    //return; Not required
}

void lowerCase(char letterfreq[], int STRSIZE)
{
    int i;

    for(i = 0; i < STRSIZE; i++)
    {
        if(letterfreq[i] >= 'A' && letterfreq[i] <= 'Z')
        {
            letterfreq[i] = letterfreq[i] + 32; //Add instead of subtract
        }
        //i++; You already increment i from the loop
    }


}

void countFreq(int counter[], int COUNT, char letterfreq[], int STRSIZE)
{
    int i=0; // You forgot to initialize i with 0

    while(letterfreq[i] != '\0')
    {   
        if(letterfreq[i] >= 'a' && letterfreq[i] <= 'z')
        {
            counter[letterfreq[i]-'a']++;
        }
        else if((letterfreq[i] < 'a') || (letterfreq[i] > 'z')) //is always true; Use `else`
        {   
            counter[COUNT-1]++;
        }

        i++; //You forgot this
    }

    //return; Not required
}

void printFreq(int counter[], int COUNT)
{
    int c;

    printf("Here is the letter frequency of your string:\n");

    for(c = 0; c < COUNT-1; c++) //See change here too
    {
        printf("%c \t %d \n", c + 'a', counter[c]);
    }

    printf("There were also %d special characters in the string.\n", counter[26]);

    //return; Not required
}

char promptReset(char reset)
{
    printf("Would you like to calculate the letter frequency of another string? (Y/N)\n");
    scanf("%c%*c", &reset);

    return(reset);
}

int main()
{
    char letterfreq[STRSIZE];
    char reset = '\0'; //Always initialize variables to prevent unexpected behavior
    int counter[COUNT];


    printf("Welcome to the Letter Frequency program\n");

    do
    {
        memset(counter,0,sizeof(counter)); //Initializing counter with zeros
        memset(letterfreq,'\0',sizeof(letterfreq)); //Do the same for letterfreq

        readString(letterfreq, STRSIZE);

        lowerCase(letterfreq, STRSIZE);

        countFreq(counter, COUNT, letterfreq, STRSIZE);

        printFreq(counter, COUNT);

        reset = promptReset(reset);

    }while(reset == 'y' || reset == 'Y'); //Changed

    return(0);
}

它还在崩溃，我哪里错了？

1 个答案: