qsort 与sort 对结构体排序实例

qsort 与sort 对结构体排序实例

#include<bits/stdc++.h>
using namespace std;

typedef struct {
	string book;
	int num;
}Book;

//qsort的比较函数
int cmp(const void * a, const void * b) {
	return (*(Book*)a).num > (*(Book*)b).num ? 1 : 0;
}

//sort的比较函数
bool cmp_(Book a, Book b) {
	return a.num > b.num;
}


int main() {
	Book Bok[3] = { {"1",4},{"2",2},{"3",3} };


	cout << endl << "----------------" << "qsort函数" << endl;
	qsort(Bok, 3, sizeof(Bok[0]),cmp);

	for (auto i : Bok) {
		cout << i.num << endl;
	}

	cout << "----------------" << "sort函数" << endl;
	sort(Bok, Bok + 3, cmp_);

	for (auto i : Bok) {
		cout << i.num << endl;
	}

	return 0;
}