两种排序介绍

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插入排序

加入数组A中有元素数为5，则排序伪代码为：

   int j =  for 1 to 5
       key = A[j];
        i = j - 1;
        for ;i >= 0 && A[i]>key;i-- {
        A[i+1] = A[i];
        }
        A[i+1] = key;

 NSMutableArray *arr = @[@32, @34, @88, @2, @44].mutableCopy;
     NSInteger key;
     NSInteger i;
    for (NSInteger j = 1; j < arr.count; j++)
    {
      key = [arr[j] integerValue];
      i = j - 1;
      for (; i >= 0 && [arr[i] integerValue] < key;i-- ){
      	arr[i + 1] = arr[i];
      	}
        arr[i+1]= @(key);
    }

选择排序

  NSMutableArray *arr = @[@32, @34, @88, @2, @44].mutableCopy;

    for (int i = 0; i < arr.count - 1; i++) {
        int flag = i;
        for (int j = i; j < arr.count; j++) {
            NSLog(@"%d -- %d -- %d", i, j, flag);
            if ([arr[flag] integerValue] - [arr[j] integerValue] > 0) {
                flag = j;
            }
        }
        NSString * tem;
        tem = arr[flag];
        arr[flag] = arr[i];
        arr[i] = tem;
    }
    NSLog(@"%@", arr);