[数据结构]集合

剑指 Offer 61. 扑克牌中的顺子

var isStraight = function(nums) {
    let max, min;
    let store = new Set();
    for (let num of nums) {
        if (num == 0) continue;
        // console.log(store)
        if (store.has(num)) return false;
        store.add(num);
        if (!max || num > max) max = num;
        if (!min || num < min) min = num;
    }
    if (max == 0 || min == 0) return true;
    return max - min + 1 <= nums.length;
};

187. 重复的DNA序列

var findRepeatedDnaSequences = function(s) {
    let n = 10;
    let subs = new Set();
    let res = new Set();
    for (let i = 0; i < s.length - n + 1; i++) {
        let sub = s.slice(i, i + n);
        if (subs.has(sub)) {
            res.add(sub);
        }
        subs.add(sub);
    }
    return [...res];
};

349. 两个数组的交集

var intersection = function(nums1, nums2) {
    let s = new Set(nums1);
    let res = new Set();
    for (let num of nums2) {
        if (s.has(num)) {
            res.add(num);
        }
    }
    return [...res];
};

961. 重复 N 次的元素

var repeatedNTimes = function(nums) {
    let s = new Set();
    for (let num of nums) {
        if (s.has(num)) return num;
        s.add(num);
    }
};