ios函数指针

//
//  main.m
//  LessionFunctionPointer
//
//  Created by laouhn on 15/7/29.
//  Copyright (c) 2015年 池海涛. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "Function.h"
int main(int argc, const char * argv[]) {
//
//    int a = 10;
//    int *p = &a;
//    printf("%d\n", *p);

    //定义结构体指针,指向结构体变量
    //结构体中包含,姓名,性别,分数,学号,新建文件实现结构体申明
//
//    Student stu1 = {"KongKong",‘w‘,19,99,"1234322"};
//    Student *sp = &stu1;
//    printf("name = %s,gender = %c,age = %d,score = %f,num = %s",sp->name,sp->Sex,sp->age,sp->score,sp->studentNum);

//   int b = maxCommon(6, 9);
//    printf("%d",b);
//    printf("%d",minCommon(6, 9));
    /**
     *  函数指针
     //函数指针
     //函数在代码区
     */
    //int (*p)(int a, int b) = maxCommon; //赋初值 maxCommon 注意,不加();

    //使用函数指针调用函数
    //int value = p(6,8);
   // printf("value = %d", value);

  //  typedef int (*PFUN)(int a, int b);

    //PFUN q = maxCommon;

    //printf("value = %d", q(3,5));

    //重定义一个无参函数
//    typedef void (*PPRINT)();
//
//    PPRINT q = printHollo;
//
//    q();

     typedef int (*PFUN)(int a, int b);
     printf("请输入数字 : 1---maxValue,2-----minValue,3---sumValue,4----subValue");

     int a = 0;
     scanf("%d",&a);
     PFUN p = NULL;
     switch (a) {
     case 1:
     p = bigNum;
     break;
     case 2:
     p = littleNum;
     break;
     case 3:
     p = sumNum;
     break;
     case 4:
     p = cutNum;
     break;
     default:
     break;
     }
     int result = p(3,5);
     printf("result == %d \n",result);
    //定义结构体数组,包含 5 个元素
    Student stu[] = {
        {"kongKong",‘w‘,27,99,"1234321"},
        {"liming",‘m‘,14,88,"432142314"},
        {"zhangxin",‘w‘,19,85,"223442113"},
        {"goushen",‘m‘,21,93,"343214"},
        {"doubi",‘w‘,45,44,"64214321"}
    };
    printStudentArray(stu,5);

    //sortByNum(stu,5);
   // sortByAge1(stu,5);
    printf("-------------------\n");
   // findStudentByScore(stu,5,addStr);
   // printStudentArray(stu,5);
    //函数回调
    //函数指针作为函数参数
    //int value = getValue(3, 5, maxCommon);
   // printf("%d",value);
    //findStudentByScore(stu,5,addStr);
    sortStudentArray(stu,5,compareByName);
    printStudentArray(stu,5);

//        printf("-------------------\n");
//    sortStudentArray(stu,5,compareByNum);
//    printStudentArray(stu,5);
    return 0;
}

//Function.h

//
//  Function.h
//  LessionFunctionPointer
//
//  Created by laouhn on 15/7/29.
//  Copyright (c) 2015年 池海涛. All rights reserved.
//

#import <Foundation/Foundation.h>

struct student{
    char name[20];
    char Sex;
    int age;
    float score;
    char *studentNum;

};
typedef struct student Student;

//函数描述:返回值为整形,有两个整形参数的函数 ,名字是max
//函数类型:int(int a,int b)---可简写为int(int,int)
//函数指针类型:int (*)(int a, int b)
//求两个数最大值
int bigNum(int a, int b);
//求两个数的最小值
int littleNum(int, int);
//求两个数的和
int sumNum(int, int);
//求两个数的差
int cutNum(int, int);
//求两个数的乘积
int  productNum(int, int);
//求两个数的商
int divide(int, int);
//求两个数的最大公约数
int maxCommon(int, int);
//求两个数的最小公倍数
int minCommon(int, int);

void printHollo();

void printStudentArray(Student *,int);
//姓名升序
void sortByName(Student *,int);
//年龄降序
void sortByAge(Student *,int);
//分数升序
void sortByScore(Student *,int);
//学号降序
void sortByNum(Student *,int);

void sortByAge1(Student[], int);
typedef int (*PFUN)(int a, int b);
int getValue(int a,int b, PFUN p);

void addStr(char *);
typedef void (*FADD)(char *);
void findStudentByScore(Student stu[],int count,void (*p)(char *));

typedef BOOL (*SORT)(Student,Student);

//姓名比较,升序
BOOL compareByName(Student stu1,Student stu2);
//年龄比较,降序
BOOL compareByAge(Student stu1,Student stu2);
//分数比较,升序
BOOL compareByScore(Student stu1,Student stu2);
//学号比较,降序
BOOL compareByNum(Student stu1,Student stu2);

//结构体数组排序

void sortStudentArray(Student stu[],int count,SORT sort);

//Function.m

//
//  Function.m
//  LessionFunctionPointer
//
//  Created by laouhn on 15/7/29.
//  Copyright (c) 2015年 池海涛. All rights reserved.
//

#import "Function.h"

//求两个数最大值
int bigNum(int a, int b)
{
    return a > b ? a : b;
}
//求两个数的最小值
int littleNum(int a, int b)
{
    return a > b ? b : a;
}
//求两个数的和
int sumNum(int a, int b)
{
    return a + b;
}
//求两个数的差
int cutNum(int a, int b)
{
    return a - b;
}
//求两个数的乘积
int  productNum(int a, int b)
{
    return a * b;
}
//求两个数的商
int divide(int a, int b)
{
    return a / b;
}
//求两个数的最大公约数
int maxCommon(int a, int b)
{
    // 9 6
    int temp = a % b ;
    while (temp != 0) {

        a = b;
        b = temp;
        temp = a % b;
    }
    return b;
}
//求两个数的最小公倍数
int minCommon(int a, int b)
{
   int temp = maxCommon(a,b);
    return (a * b) / temp;
}

void printHollo()
{
    printf("这是弄啥呢");
}

void printStudentArray(Student *sp,int count)
{
    for (int i = 0; i < count; i++) {
        printf("name = %s,gender = %c,age = %d,score = %f,num = %s \n",(sp + i)->name,(sp + i)->Sex,(sp + i)->age,(sp + i)->score,(sp + i)->studentNum);
    }

}

void sortByName(Student *a,int b)
{
    for (int i = 0; i < b - 1; i++) {
        for (int j = 0; j < b - 1 - i; j++) {
            if (strcmp((a + j)->name, (a + j + 1)->name) > 0) {
                Student temp = *(a + j);
                *(a + j) = *(a + j + 1);
                *(a + j + 1) = temp;
            }
        }
    }
}
//年龄降序
void sortByAge(Student *a,int b)
{
    for (int i = 0; i < b - 1; i++) {
        for (int j = 0; j < b - 1 - i; j++) {
            if ((a + j)->age < (a + j+ 1)->age) {
                Student temp = *(a + j);
                *(a + j) = *(a + j + 1);
                *(a + j + 1) = temp;
            }

        }
    }
}
void sortByAge1(Student str[], int a){
    for (int i = 0; i < a - 1; i++) {
        for (int j = 0; j < a - 1 - i; j++) {
            if (str[j].age < str[j + 1].age) {
                Student temp = str[j];
                str[j] = str[j + 1];
                str[j + 1] = temp;
            }
        }
    }
}
//分数升序
void sortByScore(Student *a,int b)
{
    for (int i = 0; i < b - 1; i++) {
        for (int j = 0; j < b - 1 - i; j++) {
            if ((a + j)->name > (a + j + 1)->name) {
                Student temp = *(a + j);
                *(a + j) = *(a + j + 1);
                *(a + j + 1) = temp;
            }

        }
    }
}
//学号降序
void sortByNum(Student *a,int b)
{
    for (int i = 0; i < b - 1; i++) {
        for (int j = 0; j < b - 1 - i; j++) {
            if (strcmp((a + j)->studentNum, (a + j + 1)->studentNum) < 0) {
                Student temp = *(a + j);
                *(a + j) = *(a + j + 1);
                *(a + j + 1) = temp;
            }

        }
    }
}

int getValue(int a,int b, PFUN p)
{
    return p(a,b);
}
void addStr(char *name)
{
    //*b = *b + "高富帅";
    //strcat(b,"高富帅");
    strcat(name, "高富帅");
}
void findStudentByScore(Student stu[],int count,void (*p)(char *))
{
    for (int i = 0; i < count; i++) {
        if (stu[i].score >= 90) {
            p(stu[i].name);
        }
    }
}

//姓名比较,升序
BOOL compareByName(Student stu1,Student stu2)
{
    return  strcmp(stu1.name, stu2.name) > 0 ? YES : NO;
}
//年龄比较,降序
BOOL compareByAge(Student stu1,Student stu2)
{
    return stu1.age < stu2.age ? YES : NO;
}
//分数比较,升序
BOOL compareByScore(Student stu1,Student stu2)
{
    return stu1.score > stu2.score ? YES : NO;
}
//学号比较,降序
BOOL compareByNum(Student stu1,Student stu2)
{
return  strcmp(stu1.studentNum, stu2.studentNum) < 0 ? YES : NO;
}

//结构体数组排序

void sortStudentArray(Student stu[],int count,SORT sort)
{
    for (int i = 0; i < count - 1; i++) {
        for (int j = 0; j < count - 1 - i; j++) {
            if (sort(stu[j], stu[j + 1])) {
                Student temp = stu[j];
                stu[j] = stu[j + 1];
                stu[j + 1] = temp;
            }
        }
    }
}