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;
}