84 lines
2.1 KiB
Java
84 lines
2.1 KiB
Java
//请设计一个栈，除了常规栈支持的pop与push函数以外，还支持min函数，该函数返回栈元素中的最小值。执行push、pop和min操作的时间复杂度必须为O(
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//1)。 示例： MinStack minStack = new MinStack(); minStack.push(-2); minStack.push(0);
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// minStack.push(-3); minStack.getMin(); --> 返回 -3. minStack.pop(); minStack.top
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//(); --> 返回 0. minStack.getMin(); --> 返回 -2. Related Topics 栈
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// 👍 41 👎 0
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package leetcode.editor.cn;
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import java.util.Stack;
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//面试题 03.02:栈的最小值
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public class MinStackLcci {
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public static void main(String[] args) {
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//测试代码
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// Solution solution = new MinStackLcci().new Solution();
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}
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//力扣代码
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//leetcode submit region begin(Prohibit modification and deletion)
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class MinStack {
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class Data {
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int num;
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int min;
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public Data(int num, int min) {
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this.num = num;
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this.min = min;
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}
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public int getNum() {
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return num;
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}
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public void setNum(int num) {
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this.num = num;
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}
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public int getMin() {
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return min;
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}
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public void setMin(int min) {
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this.min = min;
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}
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}
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Stack<Data> stack;
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public MinStack() {
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stack = new Stack<>();
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}
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public void push(int val) {
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if (stack.isEmpty()) {
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stack.push(new Data(val,val));
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} else {
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stack.push(new Data(val, Math.min(val, stack.peek().min)));
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}
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}
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public void pop() {
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stack.pop();
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}
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public int top() {
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return stack.peek().num;
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}
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public int getMin() {
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return stack.peek().min;
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}
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}
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/**
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* Your MinStack object will be instantiated and called as such:
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* MinStack obj = new MinStack();
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* obj.push(x);
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* obj.pop();
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* int param_3 = obj.top();
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* int param_4 = obj.getMin();
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*/
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//leetcode submit region end(Prohibit modification and deletion)
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} |