八大数据结构-数组

 

  1. 寻找数组中第二小的元素 
     1   public static int GetSecMinValue(int[] arr)
 2         {
 3             if (arr.Length < 2)
 4             {
 5                 throw new Exception("数组长度不符合要求,最小长度为2");
 6             }
 7             int FirstMinValue = Math.Min(arr[0], arr[1]);
 8             int SecMinValue = Math.Max(arr[0], arr[1]);
 9             for (int i = 0; i < arr.Length; i++)
10             {
11                 if (arr[i] < FirstMinValue)
12                 {
13                     int tmp = FirstMinValue;
14                     FirstMinValue = arr[i];
15                     SecMinValue = tmp;
16                 }
17                 else if (arr[i] < SecMinValue && arr[i] != FirstMinValue)
18                 {
19                     SecMinValue = arr[i];
20                 }
21             }
22             return SecMinValue;
23         }
    View Code
  2. 找到数组中第一个不重复出现的整数 
     1  public static int GetFirstNoRepeat(int[] arr)
 2         {
 3             foreach (int value in arr)
 4             {
 5                 int Count = arr.AsEnumerable().Where(p => p == value).Count();
 6                 if (Count == 1)
 7                     return value;
 8             }
 9             return 0;
10         }
    View Code
  3. 合并两个有序数组，自己的方案（假设数组大小从小到大） 
     1   public static int[] MergeSortedArray(int[] arr1, int[] arr2)
 2         {
 3             List<int> lst = new List<int>();
 4             int index = 0;
 5             for (int i = 0; i < arr1.Length; i++)
 6             {
 7                 while (arr1[i] >= arr2[index])
 8                 {
 9                     lst.Add(arr2[index]);
10                     index++;
11                 }
12                 lst.Add(arr1[i]);
13             }
14             for (; index < arr2.Length; index++)
15             {
16                 lst.Add(arr2[index]);
17             }
18             return lst.ToArray();
19         }
    View Code
  4. 合并两个有序数组，参考网上最优方案（假设数组大小从小到大） 
     1  public static int[] MergeSortedArray_Update(int[] arr1, int[] arr2)
 2         {
 3             if (arr1.Length == 0 && arr2.Length != 0) return arr2;
 4             if (arr2.Length == 0 && arr1.Length != 0) return arr1;
 5             if (arr1.Length == 0 && arr2.Length == 0) return new int[] { };
 6             int[] resultArr = new int[arr1.Length + arr2.Length];
 7             int arr1Index = arr1.Length - 1;
 8             int arr2Index = arr2.Length - 1;
 9             while (arr1Index >= 0)
10             {
11                 if (arr1[arr1Index] > arr2[arr2Index])
12                 {
13                     resultArr[arr1Index + arr2Index + 1] = arr1[arr1Index];
14                     arr1Index--;
15                 }
16                 else if (arr1[arr1Index] < arr2[arr2Index])
17                 {
18                     resultArr[arr1Index + arr2Index + 1] = arr2[arr2Index];
19                     arr2Index--;
20                 }
21                 else
22                 {
23                     resultArr[arr1Index + arr2Index + 1] = arr2[arr2Index];
24                     arr2Index--;
25                     resultArr[arr1Index + arr2Index + 1] = arr1[arr1Index];
26                     arr1Index--;
27                 }
28                 if (arr2Index < 0) break;
29             }
30             for (; arr2Index >= 0; arr2Index--)
31             {
32                 resultArr[arr2Index] = arr2[arr2Index];
33             }
34             for (; arr1Index >= 0; arr1Index--)
35             {
36                 resultArr[arr1Index] = arr1[arr1Index];
37             }
38             return resultArr;
39         }
    View Code
  5. 重新排列数组中的正数和负数 
     1  public static void SortedArr(int[] arr)
 2         {
 3             if (arr.Length == 0 || arr.Length == 1) return;
 4             int less = 0;
 5             int plus = 0;
 6             int index = 0;
 7             while (index < arr.Length)
 8             {
 9                 if (arr[index] < 0)
10                 {
11                     less = index;
12                     while (plus < less)
13                     {
14                         int tmp = arr[less - 1];
15                         arr[less - 1] = arr[less];
16                         arr[less] = tmp;
17                         less--;
18                     }
19                     plus = less + 1;
20                 }
21                 index++;
22             }
23         }
    View Code

     

posted @ 2019-09-20 17:11  sky&&dan  阅读(107)  评论(0)    收藏  举报