基本程序

  1. #include <iostream>
  2. #include<vector>
  3. #include<algorithm>
  5. using namespace std;
  8. int main(int argc, char** argv) {
  9.     float arr[] = { 1.0, 2.0, 3.5, 6.7, 1.22, 0.77, 90.0, 36.11 };
  10.     int arr_length = sizeof(arr) / sizeof(arr[0]);  // 数组长度
  11.     cout << "max val is: " << *max_element(arr, arr+arr_length) << "\t the max val index is " << max_element(arr, arr + arr_length)-arr << endl;
  12.     cout << "min val is: " << *min_element(arr, arr+arr_length) << "\t the min val index is " << min_element(arr, arr + arr_length) -arr<< endl;
  14.     /*
  15.     vector<double> v = {1.0, 3.55, 2.33, 4.55, 2.11, 7.66, 9.00, 7.1, 88.66, 76.99};
  16.     auto biggest =  max_element(v.begin(), v.end());
  17.     auto smallest = min_element(v.begin(), v.end());
  18.     cout << "max val is: " << *biggest << "\t the max val index is "<< distance(v.begin(), biggest)<<  endl;
  19.     cout << "min val is: " << *smallest << "\t the min val index is " << distance(v.begin(), smallest)<< endl;
  20.     */
  21.     return 0;
  22. }

细节问题

  1. #include <iostream>
  2. #include<vector>
  3. #include<algorithm>
  4. #include<random>
  5. #include<cstdlib>  // 随机数生成相关的
  6. #include<time.h>
  7. using namespace std;
  10. int main(int argc, char** argv) {
  11.     srand((unsigned)time(NULL));  // 类似于随机种子
  13.     vector<int> v_int = {};
  14.     vector<float> v_float = {};
  16.     float data;
  17.     for (int i = 0; i < 10; i++)
  18.     {
  19.         data = rand()/ double(RAND_MAX); // 生成 [0,1] 的随机数
  20.         v_int.push_back(data);
  21.         v_float.push_back(data);
  22.         cout << data << "\t";
  23.     }
  24.     cout << endl;
  25.     // 对 v_int 进行查询
  26.     auto biggest = max_element(v_int.begin(), v_int.end());
  27.     auto smallest = min_element(v_int.begin(), v_int.end());
  28.     cout << "max val is: " << *biggest << "\t the max val index is " << distance(v_int.begin(), biggest) << endl;
  29.     cout << "min val is: " << *smallest << "\t the min val index is " << distance(v_int.begin(), smallest) << endl;
  31.     return 0;
  32. }

上面运行得到的结果是下面这样，主要的原因是虽然我们加入到 float 类型的数据，但是 v_int 中元素的类型是 int 类型，所以对加入的每个元素进行强制类型转换，所以 v_int 中所有的数据都变成了 0，导致实际结果与预期不符。

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