完全暴力-选择题解

Posted 2022-01-18 icecoldless

          while (true)
            
                int.TryParse(Console.ReadLine(), out int N);
                int[] arr = new int[N];
                Random ran = new Random();
                for (int i = 0; i < arr.Length; i++)
                
                    arr[i] = ran.Next(1, 1000);
                
                Stopwatch stopwatch = new Stopwatch();
                stopwatch.Start();
                Sort(arr);
                Console.WriteLine($"第N / 2大的数为：" + arr[N / 2 - 1]);
                stopwatch.Stop();
                TimeSpan tp = stopwatch.Elapsed;
                Console.WriteLine($"程序运行：总毫秒:tp.TotalMilliseconds");
            
                
                    //从大到小
        static int[] Sort(int[] arr)
        
            int temp;
            for (int i = 0; i < arr.Length - 1; i++)
            
                for (int j = i + 1; j < arr.Length; j++)
                
                    if (arr[i] < arr[j])
                    
                        temp = arr[i];
                        arr[i] = arr[j];
                        arr[j] = temp;
                    
                
            
            return arr;
        

　　用最简单的数组索引返回k最大值，时间复杂度惨不忍睹。