C语言结构体+公用体+枚举训练

结构体大小和内存结构

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

//结构体需要根据数据类型进行内存对齐
//struct stus
//{
//    char name[20];//20
//    unsigned int age;//4
//    char tel[15];//15
//    char sex;//1  52
//    float scores[3];//12
//}stu;

struct stus
{
    //char * p;   //4
    //char arr[2];//2  8
    //short d; //2   16
    //int c;  //4 
    //long g;//4    
    //double f;//8  24
    //float h[2];//8   40


    double f;//8  24
    float h[2];//8   40
    long g;//4    
    int c;  //4 
    char * p;   //4
    short d; //2   16
    char arr[2];//2  8


    /*
    姓名：  char name[200];
    等级： int 
    当前经验：int 
    攻击： int 
    防御：int 
    技能冷却：foat 

    */


}stu;


int main()
{
    
    printf("结构体大小%d\n", sizeof(stu));

    system("pause");
    return EXIT_SUCCESS;
}

结构体学生成绩排序

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

struct stu1
{
    //成员列表
    char name[21];
    float scores[3];
};
int main()
{
    struct stu1 s[3];
    for (int i = 0; i < 3; i++)
    {
        printf("请您输入学生 姓名   成绩 ：\n");
        scanf("%s%f%f%f", s[i].name, &s[i].scores[0], &s[i].scores[1], &s[i].scores[2]);
    }
    //冒泡排序
    for (int i = 0; i < 3 - 1; i++)
    {
        for (int j = 0; j < 3 - i - 1; j++)
        {

            int sum1 = s[j].scores[0] + s[j].scores[1] + s[j].scores[2];
            int sum2 = s[j + 1].scores[0] + s[j + 1].scores[1] + s[j + 1].scores[2];
            if (sum1 > sum2)
            {
                //结构体交换   交换所有成员列表中的数据
                //交换姓名
                char temp[21] = { 0 };
                strcpy(temp, s[j].name);
                strcpy(s[j].name, s[j + 1].name);
                strcpy(s[j + 1].name, temp);

                //交换成绩

                for (int k = 0; k < 3; k++)
                {
                    float temp = s[j].scores[k];
                    s[j].scores[k] = s[j + 1].scores[k];
                    s[j + 1].scores[k] = temp;
                }

            }
        }
    }




    for (int i = 0; i < 3; i++)
    {
        printf("姓名：%s\n", s[i].name);
        printf("成绩: %.1f   %.1f   %.1f\n", s[i].scores[0], s[i].scores[1], s[i].scores[2]);
    }


    system("pause");
    return EXIT_SUCCESS;
}

学生成绩优化

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

struct stu1
{
    //成员列表
    char name[21];
    float scores[3];
};
int main()
{
    struct stu1 s[3];
    for (int i = 0; i < 3; i++)
    {
        printf("请您输入学生 姓名   成绩 ：\n");
        scanf("%s%f%f%f", s[i].name, &s[i].scores[0], &s[i].scores[1], &s[i].scores[2]);
    }
    //冒泡排序
    for (int i = 0; i < 3 - 1; i++)
    {
        for (int j = 0; j < 3 - i - 1; j++)
        {

            int sum1 = s[j].scores[0] + s[j].scores[1] + s[j].scores[2];
            int sum2 = s[j + 1].scores[0] + s[j + 1].scores[1] + s[j + 1].scores[2];
            if (sum1 > sum2)
            {
                //结构体交换   交换所有成员列表中的数据
                ////交换姓名
                //char temp[21] = { 0 };
                //strcpy(temp, s[j].name);
                //strcpy(s[j].name, s[j + 1].name);
                //strcpy(s[j + 1].name, temp);

                ////交换成绩

                //for (int k = 0; k < 3; k++)
                //{
                //    float temp=s[j].scores[k];
                //    s[j].scores[k] = s[j + 1].scores[k];
                //    s[j + 1].scores[k] = temp;
                //}

                //结构体变量交换
                struct stu1 temp = s[j];
                s[j] = s[j + 1];
                s[j + 1] = temp;

            }
        }
    }




    for (int i = 0; i < 3; i++)
    {
        printf("姓名：%s\n", s[i].name);
        printf("成绩: %.1f   %.1f   %.1f\n", s[i].scores[0], s[i].scores[1], s[i].scores[2]);
    }


    system("pause");
    return EXIT_SUCCESS;
}

结构体成员为指针

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

struct stuinfo
{
    char *name;
    int age;
};

int main()
{
    struct  stuinfo si;
    si.name = (char *)malloc(sizeof(char) * 21);

    strcpy(si.name, "张三");
    si.age = 18;

    printf("%s   %d\n", si.name, si.age);

    free(si.name);


    system("pause");
    return EXIT_SUCCESS;
}

结构体指针

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

struct sinfo
{
    char *name;
    int age;
}stu;
int main()
{
    struct sinfo * s = &stu;
    s->name = (char *)malloc(sizeof(char) * 21);
    strcpy(s->name, "李芮");
    s->age = 50;
    printf("%s   %d\n", s->name, s->age);

    free(s->name);



    system("pause");
    return EXIT_SUCCESS;
}

 

堆空间开辟结构体

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

struct tec
{
    char *name;//4
    int age;//4
}t;

int main()
{
    struct tec * p = (struct tec *)malloc(sizeof(t));
    p->name = (char *)malloc(sizeof(char) * 21);

    strcpy(p->name, "牛玲");
    p->age = 18;

    printf("%s   %d\n", p->name, p->age);

    if (p->name != NULL)
    {
        free(p->name);
        p->name = NULL;
    }

    if (p)
    {
        free(p);
        p = NULL;
    }


    printf("%d\n", sizeof(struct tec *));//无论为什么类型的指针，都是4个

    system("pause");
    return EXIT_SUCCESS;
}

 学生成绩

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
struct stu2
{
    //成员列表
    //char name[21];
    char * name;
    float * scores;
};

int main()
{
    struct stu2 *p = (struct stu2 *)malloc(sizeof(struct stu2) * 3);
    for (int i = 0; i < 3; i++)
    {
        p[i].name = (char *)malloc(sizeof(char) * 21);
        p[i].scores = (float *)malloc(sizeof(float) * 3);

        printf("请您输入学生 姓名   成绩 ：\n");
        scanf("%s%f%f%f", p[i].name, &p[i].scores[0], &p[i].scores[1], &p[i].scores[2]);

    }

    //冒泡排序
    for (int i = 0; i < 3 - 1; i++)
    {
        for (int j = 0; j < 3 - i - 1; j++)
        {
            float sum1 = p[j].scores[0] + p[j].scores[1] + p[j].scores[2];
            float sum2 = p[j + 1].scores[0] + p[j + 1].scores[1] + p[j + 1].scores[2];
            if (sum1 > sum2)
            {
                struct stu2 temp = p[j];
                p[j] = p[j + 1];
                p[j + 1] = temp;
            }
        }
    }


    for (int i = 0; i < 3; i++)
    {

        printf("姓名：%s\n", p[i].name);
        printf("成绩: %.1f   %.1f   %.1f\n", p[i].scores[0], p[i].scores[1], p[i].scores[2]);
    }


    //释放
    for (int i = 0; i < 3; i++)
    {
        free(p[i].name);
        free(p[i].scores);
    }

    free(p);



    system("pause");
    return EXIT_SUCCESS;
}

结构体和函数

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

struct info
{
    char name[21];
    int age;
};

void fun01(struct info s)
{
    strcpy(s.name, "李四");
    s.age = 20;

    printf("%s   %d\n", s.name, s.age);

}
void fun02(struct info *s)
{
    strcpy(s->name, "李四");
    s->age = 20;

}



int main1()
{
    struct info s = { "张三",18 };

    //fun01(s);
    fun02(&s);

    printf("%s   %d\n", s.name, s.age);

    system("pause");
    return EXIT_SUCCESS;
}
struct info  fun03()
{
    struct info s;
    strcpy(s.name, "李四");
    s.age = 20;

    return s;

}
struct info * fun04()
{
    struct info s;
    strcpy(s.name, "李四");
    s.age = 20;

    return &s;
}

//int fun04()
//{
//    int a = 10;
//    return a;
//}
int main()
{
    struct info s = fun03();
    printf("%s   %d\n", s.name, s.age);


    //int a = fun04();


    //struct info * s = fun04();
    //printf("%s   %d\n", s->name, s->age);
    system("pause");
    return 0;

}

 结构体嵌套结构体

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

struct stra
{
    int a;  //4   4
    float b;//4   8
    char c;//1   12  9
    char arr[7];   //16
    double h;//24
}abc;

struct  strb
{
    struct stra abc;//12  16
    short f;  //2
    char * e;  //4
    short g;
    //double d; //8
};


/*
    技能cd：
    skill01 10
    skill02 3
    skill03 7

*/
/*

    名称
    等级
    攻击
    技能：


*/
int main()
{
    struct strb  strbb;
    //strbb.d = 10.0f;
    //strbb.abc.a = 100;


    //printf("%d\n", strbb.abc.a);

    printf("%d\n", sizeof(strbb));


    system("pause");
    return EXIT_SUCCESS;
}

共用体

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

//共用体   union 共用体名称  成员列表  共用体变量名
union vars
{
    double a;
    float b;
    int c;
    short d;
    char f;
    char arr[17];//17
}var;
int main()
{
    printf("%d\n", sizeof(var));
    var.a = 100;
    var.b = 3.14;
    var.c = 66;
    printf("%f\n", var.a);
    printf("%f\n", var.b);
    printf("%d\n", var.c);

    system("pause");
    return EXIT_SUCCESS;
}

 

枚举

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

enum colors
{
    red = 10, bule, yellow = 20, black, white, green
}clo;
/*
插卡
输入密码
锁定
取款
查询
退卡
锁定解除

*/
/*
10
移动
攻击
技能
死亡
20
亮牌子
跳舞


*/
int main()
{
    clo = 0;

    int val;
    scanf("%d", &val);
    switch (val)
    {
    case red:
        break;
    case bule:
        break;
    case yellow:
        break;
    case black:
        break;
    case white:
        break;
    case green:
        break;
    default:
        break;
    }
    //switch (val)
    //{
    //case red:
    //    printf("请输入您的密码");
    //    clo = 1;
    //    printf("红色\n");
    //    break;
    //case bule:
    //    printf("");
    //    clo = 2;
    //    clo = 3;
    //    clo = 4;

    //    printf("蓝色\n");

    //    break;
    //case yellow:
    //    printf("黄色\n");

    //    break;
    //case black:
    //    break;
    //case white:
    //    break;
    //case green:
    //    break;
    //default:
    //    break;
    //}

    system("pause");
    return EXIT_SUCCESS;
}