模拟O(1)能返回最小值的栈

使用辅助来存储每次入栈后的最小值

package test;import java.util.Arrays;public class Test2 {static int max = 10;static int n = -1;static int[] stack = new int[max],hstack = new int[max];static void pop(){stack[n] = -100000;hstack[n] = 1000000;n--;}static void push(int num){stack[n+1] = num;if(n==-1 || hstack[n]>num){hstack[n+1] = num;}else{hstack[n+1] = hstack[n];}n++;}static int min(){return hstack[n];}public static void main(String[] args) {Arrays.fill(stack, -100000);Arrays.fill(hstack, 100000);push(21);System.out.println(min());push(23);System.out.println(min());push(19);System.out.println(min());push(18);System.out.println(min());pop();System.out.println(min());}}