int maxValue(int a,int b){return  a > b ? a : b;
}
int （*p）(int,int) = maxvalwe;printf("%d\n",p(3,4));  //用指针去调用函数

int maxValue(int a,int b){return  a > b ? a : b;
}
int sumValue(int a,int b){   int sum = a+b;return sum;
}
int main(int argc, const char * argv[]) {int (*p)(int,int) = NULL;int n = 0;scanf("%d",&n);switch (n) {case 1:p = maxValue;break;case 2:p = sumValue;break;default:printf("不在服务区");break;}if (p!=NULL) {printf("%d",p(3,5));}return 0;
}

typedef struct student{char name[20];char gender;int age;float score;
}Student;
void print(char *name){strcat(name, "高富帅");
}
void findvalue(Student *s,int count,void(*p)(char *)){for (int i =0; i<count; i++) {if (s[i].score > 90) {p(s[i].name);}printf("%s %c %d %f\n",s[i].name,s[i].gender,s[i].age,s[i].score);}
}
int main(int argc, const char * argv[]) {Student stu[3] = {{"xiao",'m',23,70},{"ming",'f',24,91},{"zhang",'m',28,95}};Student *s = stu;findvalue(s,3,print);return 0;
}

typedef struct student{char name[20];char gender;int age;float score;
}Student;
typedef BOOL(*sortAll)(Student stu1,Student stu2);//定义一个函数指针类型
void sortStudent(Student *s,int count,sortAll al)//函数指针指向函数(sortAge)
{for (int i = 0; i < count-1; i++) {for (int j = 0; j < count-1-i; j++) {//函数回调if (al(s[j],s[j+1])) {Student temp = s[j];s[j]  = s[j+1];s[j+1] = temp;}/*通过函数指针al指向函数(sortAge)*所以s[j],s[j+1]这两个参数也指向函数(sortAge)的形参变量stu1,stu2if(al(s[j]),s[j+1]) 等价于 if(s[j].age > s[j+1].age)*/}}for (int i =0; i<count; i++) {printf("%s %c %d %.2f\n",s[i].name,s[i].gender,s[i].age,s[i].score);}
}
BOOL sortAge(Student stu1,Student stu2)
{return stu1.age > stu2.age;
}
int main(int argc, const char * argv[]) {Student stu[3] = {{"xiao",'m',23,70},{"ming",'f',24,91},{"zhang",'m',28,95}};Student *s = stu;sortStudent(s,3,sortAge);return 0;
}