iOS开发学习之C语言---C10 函数指针-2

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// main.m

// C10 函数指针-2

// Created by 康亮亮 on 15/10/20.

#import <Foundation/Foundation.h>

#pragma mark typede函数指针

typedef struct student{

char name[20];

int age;

float score;

}Student;

// 使用typedef给函数类型重定义

// 使用PFUNC来当做函数类型的新名字

typedefBOOL (*PFUNC)(Student,Student);

// 定义一个函数，实现按照姓名升序排列

//void sortByName(Student *stu, int count){

// for (int i = 0; i < count - 1; i++) {

// for (int j = 0; j < count - 1 - i; j++) {

// if (strcmp(stu[j].name, stu[j + 1].name) > 0) {

// Student temp = stu[j];

// stu[j] = stu[j + 1];

// stu[j + 1] = temp;

// }

//}

//void sortByAge(Student *stu, int count){

// for (int i = 0; i < count - 1; i++) {

// for (int j = 0; j < count - 1 - i; j++) {

// if (stu[j].age > stu[j + 1].age) {

// Student temp = stu[j];

// stu[j] = stu[j + 1];

// stu[j + 1] = temp;

// }

//}

//void sortByScore(Student *stu, int count){

// for (int i = 0; i < count - 1; i++) {

// for (int j = 0; j < count - 1 - i; j++) {

// if (stu[j].score > stu[j + 1].score) {

// Student temp = stu[j];

// stu[j] = stu[j + 1];

// stu[j + 1] = temp;

// }

//}

// 按照成绩升序

BOOL sortByScore(Student stu1,Student stu2){

if (stu1.score > stu2.score) {

return YES;

}else

return NO;

}

// 按照姓名

BOOL sortByName(Student stu1,Student stu2){

if (strcmp(stu1.name,stu2.name) >0) {

return YES;

}else

return NO;

}

// 按照年龄

BOOL sortByAge(Student stu1,Student stu2){

if (stu1.age > stu2.age) {

return YES;

}else

return NO;

}

// 定义一个中间函数，通过这个函数的指针参数，调用不同的排序规则函数

void sortArray(Student student[],int count, PFUNC p ){

for (int i =0; i < count - 1; i++) {

for (int j =0; j < count - 1 - i; j++) {

if(p(student[j], student[j + 1])){

Student temp = student[j];

student[j] = student[j +1];

student[j +1] = temp;

}

// 封装打印函数

void printStudent(Student *stu,int count){

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

printf("%s %d %.2f\n", stu[i].name, stu[i].age, stu[i].score);

}

int main(int argc,const char * argv[]) {

//一个学生结构体数组，按照姓名给学生升序排列

Student students[5] = {

{"zhangsan",20, 65},

{"lisi",19, 75},

{"wuliu",23, 85},

{"jenny",32, 90},

{"danny",25, 96},

};

printf("按姓名排序：\n");

sortByName(students, 5);

printStudent(students, 5);

printf("按年龄排序：\n");

sortByAge(students, 5);

printStudent(students, 5);

printf("按成绩排序：\n");

sortByScore(students, 5);

printStudent(students, 5);

//根据用户输入的字符判断指针应该指向那个函数

char string[20];

printf("请输入要求：\n");

scanf("%s", string);

PFUNC p = NULL;

if (strcmp(string,"sortByName") == 0) {

p =sortByName;

}elseif(strcmp(string,"sortByAge") == 0){

p =sortByAge;

}elseif(strcmp(string,"sortByScore") == 0){

p =sortByScore;

}

if(p != NULL){

sortArray(students, 5, p);

printStudent(students, 5);

}

return 0;

}

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