八大数据结构-栈

栈

  1. 使用栈计算后缀表达式 
     1   public static void CalucatePostFix(string expression)
 2         {
 3             string[] opers = new string[] { "+", "-", "*", "/" };
 4             Stack<string> stack = new Stack<string>();
 5             string[] strs = expression.Split(' ');
 6             string result = string.Empty;
 7             foreach (string s in strs)
 8             {
 9                 if (opers.Contains(s))
10                 {
11                     double oper1 = Convert.ToDouble(stack.Pop());
12                     double oper2 = Convert.ToDouble(stack.Pop());
13                     double opresult = double.MinValue;
14                     switch (s)
15                     {
16                         case "+":
17                             opresult = oper2 + oper1;
18                             break;
19                         case "-":
20                             opresult = oper2 - oper1;
21                             break;
22                         case "*":
23                             opresult = oper2 * oper1;
24                             break;
25                         case "/":
26                             opresult = oper2 / oper1;
27                             break;
28                         default:
29                             break;
30                     }
31                     stack.Push(Convert.ToString(opresult));
32                 }
33                 else
34                 {
35                     stack.Push(s);
36                 }
37             }
38             result = stack.Pop();
39         }
    View Code
  2. 对栈中元素进行排序 
     1     public static Stack<int> SortedStack(Stack<int> stack)
 2         {
 3             Stack<int> sortStack = new Stack<int>();
 4             while (stack.Count != 0)
 5             {
 6                 int value = stack.Pop();
 7                 if (sortStack.Count == 0 || value >= sortStack.Peek())
 8                 {
 9                     sortStack.Push(value);
10                 }
11                 else
12                 {
13                     while (sortStack.Count != 0 && value < sortStack.Peek())
14                     {
15                         stack.Push(sortStack.Pop());
16                     }
17                     sortStack.Push(value);
18                 }
19             }
20             return sortStack;
21         }
    View Code
  3. 判断表达式是否括号平衡 
     1  public static bool BlanceParentheses(string exp)
 2         {
 3             bool Result = true;
 4             char[] leftparentheses = new char[] { '(', '[', '{' };
 5             char[] rightparentheses = new char[] { ')', ']', '}' };
 6             Stack<char> stack = new Stack<char>();
 7             foreach (char c in exp.ToCharArray())
 8             {
 9                 if (leftparentheses.Contains(c))
10                 {
11                     stack.Push(c);
12                 }
13                 if (rightparentheses.Contains(c))
14                 {
15                     char value = stack.Pop();
16                     switch (c)
17                     {
18                         case ')':
19                             {
20                                 if (value != '(') Result = false;
21                             }
22                             break;
23                         case ']':
24                             {
25                                 if (value != '[') Result = false;
26                             }
27                             break;
28                         case '}':
29                             {
30                                 if (value != '{') Result = false;
31                             }
32                             break;
33                     }
34                 }
35             }
36             if (stack.Count != 0)
37             {
38                 Result = false;
39             }
40             return Result;
41         }
    View Code

     

posted @ 2019-09-26 09:05  sky&&dan  阅读(83)  评论(0)    收藏  举报