（优化/未优化）冒泡排序

#include<stdio.h>

//还可以优化
void bubble_sort(int arr[], int size) {
  for (int i = 0; i < size-1; i++) { //共有size-1趟冒泡排序
    for (int j = 0; j < size-1-i; j++) 
    {
      if (arr[j] > arr[j + 1]) {
        int temp = arr[j];
        arr[j] = arr[j + 1];
        arr[j + 1] = temp;
      }
    }
  }
}
//优化后
void bubble_sort1(int arr[], int size) {
  for (int i = 0; i < size - 1; i++) {
    int flag = 1;
    for (int j = 0; j < size - 1 - i; j++) 
    {
      if (arr[j] > arr[j + 1]) {
        int temp = arr[j];
        arr[j] = arr[j + 1];
        arr[j + 1] = temp;
        flag = 0;
      }
    }
    if (flag == 1) {
      break;
    }
  }
}

int main() {
  int arr[] = { 9,8,7,6,4,5,2,1,3 };
  int arr1[] = { 9,8,7,6,4,5,2,1,3 };
  int size = sizeof(arr) / sizeof(arr[0]);

  bubble_sort(arr,size);
  for (int i = 0; i < size; i++) {
    printf("%d", arr[i]);
  }
  printf("\n");

  bubble_sort1(arr1, size);
  for (int i = 0; i < size; i++) {
    printf("%d", arr1[i]);
  }
  return 0;
}