stack::operator<

說明如何使用 stack::operator < Visual C++ 標準樣板程式庫 (STL) 函式。

template<class _TYPE, class _C, class _A>
   bool stack::operator<(
      const stack<_TYPE, _C, _A>& _X
   ) const;

備註

注意事項
在原型中的類別/參數名稱不相符的標頭檔中的版本。某些已修改以提高可讀性。

Stack::operator < 函式會傳回 true，如果運算子左邊堆疊小於右邊顯示堆疊。

如果，要判斷一個堆疊是否小於另一個堆疊

1. 最底層元素 (推入至堆疊的第一個項目) 相比較。

2. 如果不同的項目，以較小的項目堆疊小於堆疊與更大的項目。

3. 如果是相同的項目，而且有其他項目，請移至 [堆疊中的下一個項目，並返回步驟 2。

4. 如果堆疊中的所有項目會處理到目前為止，堆疊是相等的。

範例

// StackLessThan.cpp
// compile with: /EHsc
// Illustrates how to use the stack::operator<
// function to determine if one stack is less than
// another stack.
//
// Functions:
//
//    operator< :  Returns true if the stack is smaller than the stack
//                 passed as the operand.
//////////////////////////////////////////////////////////////////////

#pragma warning(disable:4786)
#include <stack>
#include <iostream>

using namespace std ;

typedef stack<double> STACK_DOUBLE;

int main()
{
   STACK_DOUBLE stack1,stack2;

   // Add item 4.0 to Stack1. Stack1 contains 4.0.
   cout << "stack1.push(4.0)  s1=[4.0]" << endl;
   stack1.push(4.0);

   // Add item 3.0 to Stack1. Stack1 contains 3.0(top) and 4.0(bottom).
   cout << "stack1.push(3.0)  s1=[3.0 4.0]" << endl;
   stack1.push(3.0);

   // Add item 4.0 to Stack2. Stack2 contains 4.0 (top=bottom).
   cout << "stack2.push(4.0)  s2=[4.0]" << endl;
   stack2.push(4.0);

   // Compare if Stack1 is smaller than Stack2. Should return False.
   cout << "stack1<stack2 is " <<
      ((stack1<stack2)? "True": "False") << endl << endl;

   // Add item 6.0 to Stack2. Stack2 contains 6.0(top) and 4.0(bottom).
   cout << "stack2.push(6.0)  s2=[6.0 4.0]" << endl;
   stack2.push(6.0);

   // Compare if Stack1 is smaller than Stack2. Should return True.
   cout << "stack1<stack2 is " <<
      ((stack1<stack2)? "True": "False") << endl << endl;

   // Add item 8.0 to Stack2. Stack2 contains 8.0(top), 6.0 and
   // 4.0(bottom).
   cout << "stack2.push(8.0)  s2=[8.0 6.0 4.0]" << endl;
   stack2.push(8.0);

   // Compare if Stack1 is smaller than Stack2. Should return True.
   cout << "stack1<stack2 is " <<
      ((stack1<stack2)? "True": "False") << endl << endl;

   // Delete item 8.0 from Stack2.
   cout << "stack2.pop()      s2=[6.0 4.0]" << endl;
   stack2.pop();

   // Delete item 6.0 from Stack2.
   cout << "stack2.pop()      s2=[4.0]" << endl;
   stack2.pop();

   // Add item 3.0 to Stack2. Stack2 contains 3.0(top) and 4.0(bottom).
   cout << "stack2.push(3.0)  s2=[3.0 4.0]" << endl;
   stack2.push(3.0);

   // Compare if Stack1 is smaller than Stack2. Should return False.
   cout << "stack1<stack2 is " <<
      ((stack1<stack2)? "True": "False") << endl << endl;

   // Delete item 3.0 from Stack2.
   cout << "stack2.pop()      s2=[4.0]" << endl;
   stack2.pop();

   // Delete item 4.0 from Stack2.
   cout << "stack2.pop()      s2=[]" << endl;
   stack2.pop();

   // Add item 8.0 to Stack2. Stack2 contains 8.0(top=bottom).
   cout << "stack2.push(8.0)  s2=[8.0]" << endl;
   stack2.push(8.0);

   // Compare if Stack1 is smaller than Stack2. Should return True.
   cout << "stack1<stack2 is " <<
      ((stack1<stack2)? "True": "False") << endl << endl;
}

Output

stack1.push(4.0)  s1=[4.0]
stack1.push(3.0)  s1=[3.0 4.0]
stack2.push(4.0)  s2=[4.0]
stack1<stack2 is False

stack2.push(6.0)  s2=[6.0 4.0]
stack1<stack2 is True

stack2.push(8.0)  s2=[8.0 6.0 4.0]
stack1<stack2 is True

stack2.pop()      s2=[6.0 4.0]
stack2.pop()      s2=[4.0]
stack2.push(3.0)  s2=[3.0 4.0]
stack1<stack2 is False

stack2.pop()      s2=[4.0]
stack2.pop()      s2=[]
stack2.push(8.0)  s2=[8.0]
stack1<stack2 is True

需求

標頭: <stack>

請參閱

概念

標準樣板程式庫範例