题目：
function Stack() { this.dataStore = []; //保存栈内元素，初始化为一个空数组 this.top = 0; //栈顶位置，初始化为0 this.push = push; //入栈 this.pop = pop; //出栈 this.peek = peek; //查看栈顶元素 this.clear = clear; //清空栈 this.length = length; //栈内存放元素的个数 this.empty = empty; //栈内存放元素的个数 } function empty() { if (this.top) { return false } else { return true } } function push(element) { this.dataStore[this.top++] = element; } function pop() { return this.dataStore[--this.top]; } function peek() { return this.dataStore[this.top - 1]; } function clear() { this.top = 0; } function length() { return this.top; } /*测试stack类的实现*/ // var s = new Stack(); // s.push("aa"); // s.push("bb"); // s.push("cc"); // console.log(s.length()); //3 // console.log(s.peek()); //cc // var popped = s.pop(); // console.log(popped); //cc // console.log(s.peek()); //bb //判断出栈入栈操作合法 // 合法出栈顺序加射程一个队列 let list_a = [4, 3, 2, 1, 0, 9, 8, 7, 6, 5] let list_b = [4, 6, 8, 7, 5, 3, 2, 9, 0, 1] let list_c = [2, 5, 6, 7, 4, 8, 9, 3, 1, 0] let list_d = [4, 3, 2, 1, 0, 5, 6, 7, 8, 9] let list_e = [1, 2, 3, 4, 5, 6, 9, 8, 7, 0] let list_f = [0, 4, 6, 5, 3, 8, 1, 7, 2, 9] let list_g = [1, 4, 7, 9, 8, 6, 5, 3, 0, 2] let list_h = [2, 1, 4, 3, 6, 5, 8, 7, 9, 0] function legalExit(list) { let temp_stack = new Stack(); let n = list.length for (let i = 0; i < n; i++) { temp_stack.push(i) while (!temp_stack.empty() && list[0] == temp_stack.peek()) { temp_stack.pop() list.shift() } } if (!temp_stack.empty()) { return false } return true } console.log('list_a', legalExit(list_a)) console.log('list_b', legalExit(list_b)) console.log('list_c', legalExit(list_c)) console.log('list_d', legalExit(list_d)) console.log('list_e', legalExit(list_e)) console.log('list_f', legalExit(list_f)) console.log('list_g', legalExit(list_g)) console.log('list_h', legalExit(list_h))
结果：
