题目不难，总结如下：

1.冒泡排序：

1    class Program 2     { 3         static void Main(string[] args) 4         { 5             string temp=Console.ReadLine(); 6             string[] tempArray=temp.Split(' '); 7             int[] arry = new int[tempArray.Length]; 8  9             for (int i = 0; i < tempArray.Length; i++)10             {11                 arry[i] = Convert.ToInt32(tempArray[i]);12                    13             }14 15             PopSort(arry, true);16             PrintArray(arry);17             PopSort(arry,false);18             PrintArray(arry);19         }20 21         static void PrintArray(int[] arry)22         {23             for (int i = 0; i < arry.Length ; i++)24             {25                 Console.Write("{0} ",arry[i]);26             }27             Console.WriteLine();28         }29 30         static void PopSort(int[] arry,bool Increase)31         {32             for(int i=0;i
      
        arry[j + 1])39                         {40                             int temp = arry[j];41                             arry[j] = arry[j + 1];42                             arry[j + 1] = temp;43                         }44                     }45                     else46                     {47                         if (arry[j] < arry[j + 1])48                         {49                             int temp = arry[j];50                             arry[j] = arry[j + 1];51                             arry[j + 1] = temp;52                         }53                     }54                 }55             }56         }57     }
      

2.字符串倒置

1  class Program 2     { 3         static void Main(string[] args) 4         { 5             string temp = Console.ReadLine(); 6             Console.WriteLine("before convert:{0}", temp); 7             StringBuilder sb = new StringBuilder(temp);           8             for (int i = 0; i < sb.Length / 2; i++) 9             {10                 char c = sb[i];11                 sb[i] = sb[sb.Length - i - 1];12                 sb[sb.Length - i - 1] = c;13                 14             }15 16             temp = sb.ToString();17             Console.WriteLine("after convert:{0}",temp);18 19 20         }21     }

3.二分法查找数组中的某个值

1  class Program 2     { 3         static void Main(string[] args) 4         { 5             int[] arry = new int[] { 23,45,67,78,100}; 6             int a=100; 7             int b = 23; 8             int c = 67; 9             int d = 40;10             Console.WriteLine("index of {0} is {1}",a, Find(arry, a));11             Console.WriteLine("index of {0} is {1}",b, Find(arry, b));12             Console.WriteLine("index of {0} is {1}",c, Find(arry, c));13             Console.WriteLine("index of {0} is {1}",d, Find(arry, d));14         }15 16         static int Find(int[] arry, int value)17         {18             int low = 0;19             int high = arry.Length;20            21 22             while (low <= high)23             {24                 int mid = (low + high) / 2;25                 if (arry[mid] == value)26                 {27                     return mid;28                 }29                 else if (arry[mid] < value)30                 {31                     low = mid + 1;32                 }33                 else34                 {35                     high = mid - 1;36                 }37 38             }39          40                 return -1;41         }42     }

4.输入数字m,n,从1,2,3...n数列中取几个数，使其和等于m，输出所有可能的组合。

1 class Program 2     { 3         static void Main(string[] args) 4         { 5             int m = 15; 6             int n = 9; 7             int[] arry = new int[n]; 8             BagProblem(m, n, arry); 9         }10 11 12         static void printArray(int[] arry)13         {14             for(int i=0;i