【LeetCode】191、461、190、118、268

191. 位1的个数

ts

function hammingWeight(n: number): number {
    const str = n.toString(2)
    let sum = 0
    for (let i = 0; i < str.length; i++) {
        if (str[i] === '1') sum++
    }
    return sum
};
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461. 汉明距离

ts

function hammingDistance(x: number, y: number): number {
    let strx = x.toString(2)
    let stry = y.toString(2)
    if (strx.length > stry.length) {
        const cha = strx.length - stry.length
        for (let i = 0; i < cha; i++) stry = '0' + stry
    } else if (stry.length > strx.length) {
        const cha = stry.length - strx.length
        for (let i = 0; i < cha; i++) strx = '0' + strx
    }
    let sum = 0
    for (let i = 0; i < strx.length; i++) {
        if (strx[i] !== stry[i]) sum++
    }
    return sum
};
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190. 颠倒二进制位

ts

function reverseBits(n: number): number {
    let str = n.toString(2)
    let cha = 32 - str.length
    for (let i = 0; i < cha; i++) {
        str = '0' + str
    }
    let sum = 0
    for(let i=0;i<str.length;i++){
        if(str[i]==='1')sum += 2**i
    }
    return sum
};
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118. 杨辉三角

ts

function generate(numRows: number): number[][] {
    let arr: number[][] = new Array
    for (let i = 0; i < numRows; i++) {
        let len = i + 1
        let _arr: number[] = new Array
        _arr[0] = 1
        _arr[len - 1] = 1
        if (len > 2) {
            for (let i2 = 1; i2 < len - 1; i2++) {
                _arr[i2] = arr[i - 1][i2 - 1] + arr[i - 1][i2]
            }
        }
        arr.push(_arr)
    }
    return arr
};
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268. 丢失的数字

ts

function missingNumber(nums: number[]): number {
    const arr = nums.sort((a, b) => a - b)
    for (let i = 0; i < arr.length; i++) {
        if (arr[i] !== i) return i
    }
    return arr.length
};
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