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ART4

Algorithm

比特位计数 LeetCode #338

给定一个非负整数 num。对于 0 ≤ i ≤ num 范围中的每个数字 i ,计算其二进制数中的 1 的数目并将它们作为数组返回。

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class Solution {
fun countBits(num: Int): IntArray {
val bits = IntArray(num + 1)
for (i in 1..num) {
bits[i] = bits[i.shr(1)] + (i and 1)
}
return bits
}
}

ARTS3

Algorithm

滑动窗口 LeetCode #1243

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fun maxScore(cardPoints: IntArray, k: Int): Int {
val range = cardPoints.size - k
var sum = 0
repeat(range) {
sum += cardPoints[it]
}
var minSum = sum
var tempSum = sum
for (i in range until cardPoints.size) {
sum += cardPoints[i]
tempSum += cardPoints[i] - cardPoints[i - range]
minSum = minOf(minSum, tempSum)
}
return sum - minSum
}

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Tip

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Room 新增表和索引时,Migration 的写法

RecyclerView#scrollToPositionRecyclerView#scrollToPositionWithOffset 区别

Android Studio 返回上一步操作快捷键 win: ctrl + alt + ← mac: option + command + ←

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ARTS2

Algorithm

Review

Tip

ViewOutlineProvider

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CSS 实现 Android 图片的 centerInside 效果

  1. 图片父布局的 style

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    .parent {
    display: flex;
    align-items: center;
    justify-content: center;
    }
  2. 图片的 style

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    .img {
    max-width: 100%;
    max-height: 100%;
    }