c++ - C++中结构数组元素的最小值和索引

Question

问题:

#include <iostream>
#include <algorithm>
using namespace std;

struct abc
{
   int cost;
   int any;
};

int main() {
abc *var1 = new abc[5];
   var1[0].cost = 4;
   var1[1].cost = 42;
   var1[2].cost = 5;
   var1[3].cost = 0;
   var1[4].cost = 12;

  //       cout<< "value = " << *std::min_element(var1.cost,var1.cost+5) << endl;
  //       cout << "Position = " << (std::min_element(var1.cost,var1.cost+5)-var1.cost) << endl;
    return 0;
}

如何找到var1[].cost的最小值和位置？是否可以使用 std::min_element 找到它？

Answer 1

std::min_element - cppreference.com

您可以使用比较函数对象让 std::min_element 查看成员 cost。

#include <iostream>
#include <algorithm>
using namespace std;

struct abc
{
   int cost;
   int any;
};

struct cmp_abc {
  bool operator()(const abc& a, const abc& b) const {
    return a.cost < b.cost;
  }
};

int main() {
   abc *var1 = new abc[5];
   var1[0].cost = 4;
   var1[1].cost = 42;
   var1[2].cost = 5;
   var1[3].cost = 0;
   var1[4].cost = 12;

   abc *res = std::min_element(var1, var1 + 5, cmp_abc());

   cout << "value = " << res->cost << endl;
   cout << "Position = " << (res - var1) << endl;

   delete[] var1;
   return 0;
}