53 lines
1.0 KiB
JavaScript
53 lines
1.0 KiB
JavaScript
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export class PriorityQueue {
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constructor() {
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this.val = [null];
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}
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push(value, priority) {
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if (priority == null) {
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priority = value;
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}
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this.val.push([value, priority]);
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let id = this.val.length - 1;
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while (id > 1 && this.val[id][1] > this.val[id >>> 1][1]) {
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const kid = id >>> 1;
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[this.val[id], this.val[kid]] = [this.val[kid], this.val[id]];
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id = kid;
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}
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return this;
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}
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pop() {
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let lv = this.val.pop();
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if (this.val.length == 1) { return lv; }
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let res = this.val[1];
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this.val[1] = lv;
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let id = 1;
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while (id * 2 < this.val.length) {
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if (this.val[id][1] > this.val[id * 2][1] && (id * 2 + 1 >= this.val.length || this.val[id][1] > this.val[id * 2 + 1][1])) {
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break;
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}
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let kid = (id * 2 + 1 >= this.val.length || this.val[id * 2][1] > this.val[id * 2 + 1][1]) ? id * 2 : id * 2 + 1;
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[this.val[id], this.val[kid]] = [this.val[kid], this.val[id]];
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id = kid;
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}
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return res;
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}
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top() {
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return this.val[1];
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}
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size() {
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return this.val.length - 1;
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}
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empty() {
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return this.size() == 0;
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}
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};
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