前端算法之TypeScript包含min函数的栈实例详解

const stack = [
  3,
  5,
  7
  12,
  1,
  9,
  0
]

export class StackContainingMinFunction extends Stack {
  private minStack: Stack;
  private dataStack: Stack;
  constructor() {
    super();
    this.minStack = new Stack();
    this.dataStack = new Stack();
  }
  public push(item: number): void {
    this.dataStack.push(item);
    if (this.minStack.size() > 0) {
      const minVal = this.minStack.peek();
      // 比较当前入栈元素与minStack中的最小元素，将小的一方入minStack
      item > minVal ? this.minStack.push(minVal) : this.minStack.push(item);
      return;
    }
    this.minStack.push(item);
  }
  public pop(): void {
    this.minStack.pop();
    this.dataStack.pop();
  }
  public min(): number | null {
    if (this.minStack.size() > 0) return this.minStack.peek();
    return null;
  }
}

const stackMinFn = new StackContainingMinFunction();
stackMinFn.push(3);
stackMinFn.push(5);
stackMinFn.push(7);
stackMinFn.push(12);
stackMinFn.push(1);
stackMinFn.push(9);
stackMinFn.push(0);
stackMinFn.pop();
stackMinFn.pop();
stackMinFn.pop();
console.log("当前栈内最小值为:", stackMinFn.min());