@figliolia/data-structures/dist/mjs/MinStack.js

Efficient data structures for every day programming

import { MinMaxStack } from "./MinMaxStack.js";
/**
 * Min Stack
 *
 * A stack maintaining a reference to it's lowest weighted item
 *
 * ```typescript
 * import { MinStack } from "@figliolia/data-structures";
 *
 * const stack = new MinStack<number>(value => value);
 * stack.push(3); // min = 3
 * stack.push(2); // min = 2
 * stack.push(1); // min = 1
 * stack.min // 1
 * stack.pop() // min = 2
 * ```
 */
export class MinStack extends MinMaxStack {
    min = null;
    get minimum() {
        return this.min === null ? null : this.extract(this.min);
    }
    setMinMax(val) {
        const value = this.extract(val);
        const min = this.minimum;
        if (min === value) {
            this.occurances++;
            return;
        }
        if (min === null || value < min) {
            this.min = val;
            this.occurances = 1;
        }
    }
    findMinMax(val) {
        const value = this.extract(val);
        if (value === this.minimum) {
            this.occurances--;
            if (this.occurances === 0) {
                this.findMin();
            }
        }
    }
    findMin() {
        let occurances = 0;
        let minValue = null;
        let min = null;
        for (const value of this.storage) {
            const currentValue = this.extract(value);
            if (minValue === null || currentValue < minValue) {
                min = value;
                occurances = 1;
                minValue = currentValue;
            }
            else if (minValue === currentValue) {
                occurances++;
            }
        }
        this.min = min;
        this.occurances = occurances;
    }
}