Question

c++如何对自定义结构体排序

Answer 1

重载要排序的结构体或类的<号或者号，演示代码如下： #include<vector #include<algorIThm using namespace std; typedef struct ValuePerWeight //定义结构体{double vw;int i;bool operator <(const ValuePerWeight &other)const //升序排序{return vwother.vw;}//或者bool operator (const ValuePerWeight &r)const //降序排序{return vwother.vw;}}ValuePerWeight; int main(){ ValuePerWeight a1..an; vector<ValuePerWeight vpw ; for(int i=1;i<=n;i++){ vpw.push_back(ai);//对a1到an处理后加到vpw}sort(vpw.begin(), vpw.end(),greater<ValuePerWeight());//降序 sort(vpw.begin(), vpw.end(),less<ValuePerWeight());//升序 //默认情况为升序 sort(vpw.begin(), vpw.end()) return 0;}不修改结构体或类的定义部分，用函数对象来实现，演示代码如下： #include<vector #include<algorIThm #include <functional using namespace std; typedef struct ValuePerWeight//自定义结构体{double vw;int i; }ValuePerWeight;//全局函数bool a_less_b(const ValuePerWeight& r,const ValuePerWeight& s){return r.vw < s.vw;}bool a_greater_b(const ValuePerWeight& r,const ValuePerWeight& s){return r.vw s.vw;}int main(){ ValuePerWeight a1..an; vector<ValuePerWeight vpw ; for(int i=1;i<=n;i++){ vpw.push_back(ai);//对a1到an处理后加到vpw}sort(vpw.begin(), vpw.end(),a_less_b); //升序排序 sort(vpw.begin(), vpw.end(),a_greater_b); //降序排序 其他：这两天做0-1背包多解法的综合实验，其中用到贪心算法需要对输入的物品进行价值密度的排序。