計數排序

#include <iostream>
using namespace std;
const int N = 10;

int maxm(int arr[], int n) {
  int max = arr[0];
  for (int i = 1; i < n; i++) {
    if (arr[i] > max) {
      max = arr[i];
    }
  }
  return max;
}

int minm(int arr[], int n) {
  int min = arr[0];
  for (int i = 1; i < n; i++) {
    if (arr[i] < min) {
      min = arr[i];
    }
  }
  return min;
}

void countingSort(int arr[], int n) {
  int min = minm(arr, n);
  int max = maxm(arr, n);
  int range = max - min + 1;
  int count[range] = {};
  int output[n];
  for (int i = 0; i < n; i++) count[arr[i] - min]++;

  for (int i = 1; i < range; i++) count[i] += count[i - 1];

  for (int i = n - 1; i >= 0; i--) {
    output[count[arr[i] - min] - 1] = arr[i];
    count[arr[i] - min]--;
  }

  for (int i = 0; i < n; i++) arr[i] = output[i];
}

int main() {
  int n = 7;
  int arr[7] = {3, 5, 1, 1, 4, 2, 1};
  cout << "Input arr: ";
  for (int i = 0; i < n; i++) {
    cout << arr[i] << " ";
  }
  cout << "\n";
  countingSort(arr, n);  // Sort elements in ascending order
  cout << "Output arr: ";
  for (int i = 0; i < n; i++) {
    cout << arr[i] << " ";
  }
  cout << "\n";
}