深拷贝/斐波拉切/快排/冒泡排序/二分法查找

几个前端常用的算法

深拷贝

function deepClone(o1, o2) {
    for (let k in o2) {
        if (typeof o2[k] === 'object') {
            if (o2[k] instanceof Array) {
                o1[k] = []
            } else {
                o1[k] = {}
            }
            deepClone(o1[k], o2[k])
        } else {
            o1[k] = o2[k]
        }
    }
}

斐波拉切中的第几项

let count = 0
function fn(n) {
    let cache = {}
    function _fn(n) {
        if (cache[n]) {
            return cache[n]
        }
        count++
        if (n === 1 || n === 2) {
            return 1
        }
        let prev = _fn(n-1)
        cache[n-1] = prev
        let next = _fn(n-2)
        cache[n-2] = next
        return prev + next
    }
    return _fn(n)
}

快速排序

const Arr = [86, 71, 23, 24, 65, 45, 31, 96, 50]
function quickSort (arr) {
    if (arr.length < 1) {
        return arr
    }
    let pivotIndex = Math.floor(arr.length/2)
    let pivot = arr.splice(pivotIndex, 1)[0]
    let left = []
    let right = []
    for (let i =0; i < arr.length; i++) {
        if (arr[i] < pivot) {
            left.push(arr[i])
        } else {
            right.push(arr[i])
        }
    }
    return quickSort(left).concat([pivot, quickSort(right)])
}
console.log(Arr)

二分法查找

function Find(target, array) {
    let i = 0;
    let j = array[i].length -1
    while (i < array.length && j >= 0) {
        if (array[i][j] < target) {
            i++
        } else if (arrar[i][j] > target) {
            j--
        } else {
            return true
        }
    }
    return false
}
console.log(Find(10, [[1, 2, 3, 4], [6, 9, 11], [13, 20, 23]]))

冒泡排序

for (let i =0; i < score.length -1; i++) {
    for (let j =0; j < score.length - 1 - i; j++) {
        if (score[j] < score[j + 1]) {
            let temp = score[j]
            score[j] = score[j + 1]
            score[j + 1] = temp
        }
    }
}

赏

1分也是爱

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