【C++简明教程】找数组或者Vector中最大最小值的索引

max_element(arr, arr+arr_length) //arr 是数组，arr_length 是数组长度
max_element(v.begin(), v.end()) // v 是 vector数据结构

#include <iostream>
#include<vector>
#include<algorithm>

using namespace std;


int main(int argc, char** argv) {
 float arr[] = { 1.0, 2.0, 3.5, 6.7, 1.22, 0.77, 90.0, 36.11 };
 int arr_length = sizeof(arr) / sizeof(arr[0]);  // 数组长度
  // max_element(arr, arr+arr_length) 计算出来是一个地址，我们需要取该地址的值
 cout << "max val is: " << *max_element(arr, arr+arr_length) << "\t the max val index is " << max_element(arr, arr + arr_length)-arr << endl;
 cout << "min val is: " << *min_element(arr, arr+arr_length) << "\t the min val index is " << min_element(arr, arr + arr_length) -arr<< endl;

 /*
 vector<double> v = {1.0, 3.55, 2.33, 4.55, 2.11, 7.66, 9.00, 7.1, 88.66, 76.99};
 auto biggest =  max_element(v.begin(), v.end());
 auto smallest = min_element(v.begin(), v.end());
 cout << "max val is: " << *biggest << "\t the max val index is "<< distance(v.begin(), biggest)<<  endl;
 cout << "min val is: " << *smallest << "\t the min val index is " << distance(v.begin(), smallest)<< endl;
 */
 return 0;
}

#include <iostream>
#include<vector>
#include<algorithm>
#include<random>
#include<cstdlib>  // 随机数生成相关的
#include<time.h>
using namespace std;


int main(int argc, char** argv) {
 srand((unsigned)time(NULL));  // 类似于随机种子
    
 vector<int> v_int = {};
 vector<float> v_float = {};
 
    float data;
 for (int i = 0; i < 10; i++)
 {
  data = rand()/ double(RAND_MAX); // 生成 [0,1] 的随机数
  v_int.push_back(data);
  v_float.push_back(data);
  cout << data << "\t";
 }
 cout << endl;
  // 对 v_int 进行查询
 auto biggest = max_element(v_int.begin(), v_int.end());
 auto smallest = min_element(v_int.begin(), v_int.end());
 cout << "max val is: " << *biggest << "\t the max val index is " << distance(v_int.begin(), biggest) << endl;
 cout << "min val is: " << *smallest << "\t the min val index is " << distance(v_int.begin(), smallest) << endl;

 return 0;
}