增加淘宝群内容，修改部分文件组织

数据结构(双语)/数据结构 day16【瑞客论坛 www.ruike1.com】/代码/00-leetcode/src/栈/_20_有效的括号.java

@@ -0,0 +1,63 @@
+package 栈;
+
+import java.util.HashMap;
+import java.util.Stack;
+
+public class _20_有效的括号 {
+	private static HashMap<Character, Character> map = new HashMap<>();
+	static {
+		// key - value
+		map.put('(', ')');
+		map.put('{', '}');
+		map.put('[', ']');
+	}
+	
+	public boolean isValid(String s) {
+		Stack<Character> stack = new Stack<>();
+		
+		int len = s.length();
+		for (int i = 0; i < len; i++) {
+			char c = s.charAt(i);
+			if (map.containsKey(c)) { // 左括号
+				stack.push(c);
+			} else { // 右括号
+				if (stack.isEmpty()) return false;
+				
+				if (c != map.get(stack.pop())) return false;
+			}
+		}
+		return stack.isEmpty();
+    }
+	
+	public boolean isValid1(String s) {
+		Stack<Character> stack = new Stack<>();
+		
+		int len = s.length();
+		for (int i = 0; i < len; i++) {
+			char c = s.charAt(i);
+			if (c == '(' || c == '{' || c == '[') { // 左括号
+				stack.push(c);
+			} else { // 右括号
+				if (stack.isEmpty()) return false;
+				
+				char left = stack.pop();
+				if (left == '(' && c != ')') return false;
+				if (left == '{' && c != '}') return false;
+				if (left == '[' && c != ']') return false;
+			}
+		}
+		return stack.isEmpty();
+    }
+
+	public boolean isValid2(String s) {
+		while (s.contains("{}")
+				|| s.contains("[]")
+				|| s.contains("()")) {
+			s = s.replace("{}", "");
+			s = s.replace("()", "");
+			s = s.replace("[]", "");
+		}
+		return s.isEmpty();
+    }
+	
+}

数据结构(双语)/数据结构 day16【瑞客论坛 www.ruike1.com】/代码/00-leetcode/src/栈/_232_用栈实现队列.java

@@ -0,0 +1,44 @@
+package 栈;
+
+import java.util.Stack;
+
+public class _232_用栈实现队列 {
+	private Stack<Integer> inStack;
+	private Stack<Integer> outStack;
+
+    /** Initialize your data structure here. */
+    public _232_用栈实现队列() {
+    	inStack = new Stack<>();
+    	outStack = new Stack<>();
+    }
+    
+    /** 入队 */
+    public void push(int x) {
+        inStack.push(x);
+    }
+    
+    /** 出队 */
+    public int pop() {
+    	checkOutStack();
+    	return outStack.pop();
+    }
+    
+    /** 获取队头元素 */
+    public int peek() {
+    	checkOutStack();
+    	return outStack.peek();
+    }
+    
+    /** 是否为空 */
+    public boolean empty() {
+    	return inStack.isEmpty() && outStack.isEmpty();
+    }
+    
+    private void checkOutStack() {
+    	if (outStack.isEmpty()) {
+        	while (!inStack.isEmpty()) {
+        		outStack.push(inStack.pop());
+        	}
+        }
+    }
+}