力扣2296.设计一个文本编辑器

• 对顶栈

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  • 将光标看作左右栈的分隔
  • 添加元素：往左栈添加元素
  • 删除元素：从左栈删除元素
  • 光标左(右)移：左(右)栈元素加到右(左)栈

•   class TextEditor {string left,right;public:TextEditor() {}void addText(string text) {left += text;}int deleteText(int k) {k = min(k,(int)left.size());left.resize(left.size() - k);return k;}string text(){return left.substr(max((int)left.size() - 10,0));}string cursorLeft(int k) {for(;k && !left.empty();k--){right += left.back();left.pop_back();}return text();}string cursorRight(int k) {for (; k && !right.empty(); --k) {left += right.back();right.pop_back();}return text();}};