如何在C控制台程序中将字符串用户输入与int变量相匹配

Question

我想做一个简单的程序，像商店系统。长话短说，我希望我的用户输入代码(这是var name和int价格值(示例输入："a1 a2 b3 ... "))然后它可以计算出它的最终价格(fp = a1+a2+a3+...)并添加一些“人工自动”的进度条或加载条

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

int main() {
char sel;
int i,s;
int fp;
        
        //var name and price list
int mma1 = 2500;
int mma2 = 2000;
int mma3 = 3000;
int mma4 = 3500;

int mmb1 = 10000;
int mmb2 = 12000;
int mmb3 = 13000;
int mmb4 = 10000;

int mmc1 = 7000;
int mmc2 = 7500;
int mmc3 = 6500;
int mmc4 = 5000;

int mmd1 = 2000;
int mmd2 = 1500;
int mmd3 = 3000;
int mmd4 = 3500;

int mka1 = 3000;
int mka2 = 12000;
int mka3 = 10000;
int mka4 = 11000;

int mkb1 = 6000;
int mkb2 = 5000;
int mkb3 = 7000;
int mkb4 = 5500;

int mkc1 = 12000;
int mkc2 = 15000;
int mkc3 = 15000;
int mkc4 = 13000;

int mkd1 = 45000;
int mkd2 = 50000;
int mkd3 = 55000;
int mkd4 = 60000;
        
for(i=0; i<=7; i++)
    {
        
        
        //list
        char b=64, a[8][4][50]=
    {
        "proto1 = 2500", "proto2 = 2000", "proto3 = 3000", "proto4 = 3500",
        "proto5 = 10000", "proto6 = 12000", "proto7 = 13000", "proto8 = 10000",
        "proto9 = 7000", "proto10 = 7500", "proto11 = 6500","proto12 = 5000",
        "proto13 = 2000", "proto14 = 1500", "proto15 = 3000", "proto16 = 3500",
        "proto17 = 3000", "proto18 = 12000", "proto19 = 10000", "proto20 = 11000",
        "proto21 = 6000", "proto22 = 5000", "proto23 = 7000", "24 = 5500",
        "proto25= 12000", "26 = 15000", "27 = 15000", "28 = 13000",
        "29 = 45000", "30 = 50000", "31 = 55000", "32 = 60000"
    };
    
    
            for(i=0; i<=7; i++)
    {
        
        if(i==0)
        {
            printf("================================================================================================================================");
            printf("\nMenyediakan\n");
            printf("\n mm\n");
        }   
        else
        if(i==4)
        {
            printf("================================================================================================================================");
            printf("\nMenyediakan\n");
            printf("\n mk\n");
            b=64;
        }
        b++;
        printf("type %c  \n", b);
        
        for(s=0; s<=3; s++)
        {
            printf("      %d. %s \n", s+1, a[i][s]);
            
        }
        
        printf("\n");
    }
    printf("================================================================================================================================\n");
    
    
        
  
    printf("type all code of your desired item then press enter (example 'mma1 mma3 mkb3 mkb4 ... ')\n");
    scanf("%s", sel);
    // 
    
    fp = 
    
    //
    system("pause");
    return 0;
}
}

这个"fp =“部分是我想知道任何参考都会被接受，任何建议都会被接受，任何选项也会被接受，比如使用call函数等

非常感谢

Answer 1

我通常是一小步一步来的。您已经到了int fp = <???>;步骤...因此，请记住，拥有很多函数是很好的：

fp = finalPrice(sel); // may need more arguments

并且，对于版本0.0.0.0.1

int finalprice(const char *input) {
    return 42;
}

检查它是否正常工作，然后添加功能。

版本0.0.0.0.2

int finalprice(const char *input) {
    if (*input == 'a') return 65;
    return -1;
}

不断改变函数，直到它对一堆测试输入“起作用”。

Answer 2

这显然是一个矩阵操作练习。

您应该从表(矩阵)中获取产品价格，而不是从单个变量中获取。创建一个包含价格的表：

char product_prices_table[8][4][50]=
{
    /* mma */
    "2500",  "2000",   "3000",  "3500",
    /* mmb */
    "10000", "12000",  "13000", "10000",
    /* mmc */
    "7000",  " 7500",  "6500",  "5000",
    /* mmd */
    "2000",  " 1500",  "3000",  "3500",
    /* mka */
    "3000",  " 12000", "10000", "11000",
    /* mkb */
    "6000",  " 5000",  "7000",  "5500",
    /* mkc */
    "12000", "15000", "15000", "13000",
    /* mkd */
    "45000", "50000", "55000", "60000"
};

此外，您应该将所有变量初始化为零，并确保变量sel包含足够的空间来存储用户输入。我将其声明更改为包含1024个字符(这是一个任意值)。

int fp = 0;
char sel[1024] = {0, };

scanf("%s", sel)不限制读取的字符数，也不包括空格，因此请将其更改为fgets(sel, 1024, stdin);。

现在，创建一个函数来根据产品代码获取价格(从product_prices_table)。

static int get_product_price(char *product_code)
{
    int product_price = 0;

    /* Ensure input is valid */
    if (   (strlen(product_code) == 4)
        && (product_code[0] == 'm')
        && (product_code[1] == 'm' || product_code[1] == 'k')
        && (product_code[2] >= 'a' && product_code[2] <= 'd')
        && (product_code[3] >= '1' && product_code[3] <= '4'))
    {
        /* Get price from the table */
        int first_index = 0;

        if (product_code[1] == 'k')
            first_index = 4;

        if (product_code[2] == 'b')
            first_index += 1;
        else if (product_code[2] == 'c')
            first_index += 2;
        else if (product_code[2] == 'd')
            first_index += 3;

        int second_index = atoi(&product_code[3]) - 1;

        product_price = atoi(product_list[first_index][second_index]);
    }
    else
    {
        printf("error: invalid product code \"%s\"\n", product_code);
    }

    return product_price;
}

在您的main函数中，循环输入并使用每个产品代码调用您的函数，并在您的fp变量中进行累积。

/* Loop through all provided product codes */
int input_size = strlen(sel);
char *product_code = sel;

int i = 0;
for (; i < input_size; i++) {

    /* Check for end of product code */
    if (sel[i] == ' ' || (i == input_size - 1)) {

        /* Discard trailing whitespace or the last newline character */
        if (sel[i] == ' ' || sel[i] == '\n')
            sel[i] = 0;

        fp += get_product_price(product_code);

        /* Point to the next product code */
        if (i + 1 < input_size)
            product_code = &sel[i + 1]; 
    }   
}   

所以现在fp有了所有提供的产品的总价。

下面是完整的代码：

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

#include <string.h>

char product_prices_table[8][4][50]=
{
    /* mma */
    "2500",  "2000",   "3000",  "3500",
    /* mmb */
    "10000", "12000",  "13000", "10000",
    /* mmc */
    "7000",  " 7500",  "6500",  "5000",
    /* mmd */
    "2000",  " 1500",  "3000",  "3500",
    /* mka */
    "3000",  " 12000", "10000", "11000",
    /* mkb */
    "6000",  " 5000",  "7000",  "5500",
    /* mkc */
    "12000", "15000", "15000", "13000",
    /* mkd */
    "45000", "50000", "55000", "60000"
};
    
static int get_product_price(char *product_code)
{
    int product_price = 0;

    /* Ensure input is valid */
    if (   (strlen(product_code) == 4)
        && (product_code[0] == 'm')
        && (product_code[1] == 'm' || product_code[1] == 'k')
        && (product_code[2] >= 'a' && product_code[2] <= 'd')
        && (product_code[3] >= '1' && product_code[3] <= '4'))
    {
        /* Get price from the table */
        int first_index = 0;

        if (product_code[1] == 'k')
            first_index = 4;

        if (product_code[2] == 'b')
            first_index += 1;
        else if (product_code[2] == 'c')
            first_index += 2;
        else if (product_code[2] == 'd')
            first_index += 3;

        int second_index = atoi(&product_code[3]) - 1;

        product_price = atoi(product_prices_table[first_index][second_index]);
    }
    else
    {
        printf("error: invalid product code \"%s\"\n", product_code);
    }

    return product_price;
}

int main() {
    char sel[1024] = {0, };
    int i,s;
    int fp = 0;
            
    for(i=0; i<=7; i++)
        {
            
        //list
             char b=64, a[8][4][50]=
         {
             "proto1 = 2500", "proto2 = 2000", "proto3 = 3000", "proto4 = 3500",
             "proto5 = 10000", "proto6 = 12000", "proto7 = 13000", "proto8 = 10000",
             "proto9 = 7000", "proto10 = 7500", "proto11 = 6500","proto12 = 5000",
             "proto13 = 2000", "proto14 = 1500", "proto15 = 3000", "proto16 = 3500",
             "proto17 = 3000", "proto18 = 12000", "proto19 = 10000", "proto20 = 11000",
             "proto21 = 6000", "proto22 = 5000", "proto23 = 7000", "24 = 5500",
             "proto25= 12000", "26 = 15000", "27 = 15000", "28 = 13000",
             "29 = 45000", "30 = 50000", "31 = 55000", "32 = 60000"
         };

        for(i=0; i<=7; i++)
        {
            
            if(i==0)
            {
                printf("================================================================================================================================");
                printf("\nMenyediakan\n");
                printf("\n mm\n");
            }   
            else
            if(i==4)
            {
                printf("================================================================================================================================");
                printf("\nMenyediakan\n");
                printf("\n mk\n");
                b=64;
            }
            b++;
            printf("type %c  \n", b);
            
            for(s=0; s<=3; s++)
            {
                printf("      %d. %s \n", s+1, a[i][s]);
                
            }
            
            printf("\n");
        }
        printf("================================================================================================================================\n");
      
        printf("type all code of your desired item then press enter (example 'mma1 mma3 mkb3 mkb4 ... ')\n");
        fgets(sel, 1024, stdin);

        /* Loop through all provided product codes */
        int input_size = strlen(sel);
        char *product_code = sel;

        int i = 0;
        for (; i < input_size; i++) {

            /* Check for end of product code */
            if (sel[i] == ' ' || (i == input_size - 1)) {

                /* Discard trailing whitespace or the last newline character */
                if (sel[i] == ' ' || sel[i] == '\n')
                    sel[i] = 0;

                fp += get_product_price(product_code);

                /* Point to the next product code */
                if (i + 1 < input_size)
                    product_code = &sel[i + 1];
            }
        }

        printf("fp = %d\n", fp);

        //
        system("pause");
        return 0;
    }
}