Unresolved reference: TimeChangeReceiver

"Unresolved reference: TimeChangeReceiver" is an error message that typically occurs in programming when the code references a variable or function that has not been defined or imported correctly. To resolve this particular error, you need to make sure that the TimeChangeReceiver class is properly defined and imported in your code. You may also need to check for typos or syntax errors in your code that could be causing the issue.

相关问题

Line 5: Char 28: error: unresolved reference: pow while(x.toDouble().pow(i)<bound){ ^ Line 7: Char 32: error: unresolved reference: pow while(x.toDouble().pow(i)+y.toDouble().pow(j)<=bound){ ^ Line 7: Char 52: error: unresolved reference: pow while(x.toDouble().pow(i)+y.toDouble().pow(j)<=bound){ ^ Line 8: Char 39: error: unresolved reference: pow set.add((x.toDouble().pow(i)+y.toDouble().pow(j)).toInt()) ^ Line 8: Char 59: error: unresolved reference: pow set.add((x.toDouble().pow(i)+y.toDouble().pow(j)).toInt())

抱歉，我的代码中使用了 Kotlin 的扩展函数 Math.pow()，但是在 Kotlin 中没有这个函数，需要使用 Kotlin 标准库中的 kotlin.math 库的函数。您可以将代码修改为：

import kotlin.math.pow

fun powerfulIntegers(x: Int, y: Int, bound: Int): List<Int> {
    val set = mutableSetOf<Int>()
    var i = 0
    while (x.toDouble().pow(i) < bound) {
        var j = 0
        while (x.toDouble().pow(i) + y.toDouble().pow(j) <= bound) {
            set.add((x.toDouble().pow(i) + y.toDouble().pow(j)).toInt())
            if (y == 1) break
            j++
        }
        if (x == 1) break
        i++
    }
    return set.toList()
}

这样就可以正确地使用 pow() 函数了。

上述代码存在这个问题：Line 4: Char 22: error: unresolved reference: maxByOrNull val m = nums.maxByOrNull { it.size }?.size ?: 0 ^ Line 4: Char 36: error: unresolved reference: it val m = nums.maxByOrNull { it.size }?.size ?: 0 ^

这个问题是由于 `maxByOrNull` 函数在 Kotlin 1.3 版本之前不存在所导致的。

你可以将代码中的 `maxByOrNull` 函数替换成 `maxBy` 函数，并且在后面添加 `?.size`，这样就可以解决问题了。修改后的代码如下：

fun findDiagonalOrder(nums: List<List<Int>>): IntArray {
    val n = nums.size
    val m = nums.maxBy { it.size }?.size ?: 0
    val res = IntArray(n * m)

    var k = 0
    for (i in 0 until n + m - 1) {
        for (j in 0..i) {
            val x = j
            val y = i - j
            if (x >= n || y >= m) continue
            res[k++] = nums[x][y]
        }
        if (i % 2 == 0) {
            var l = k - 1
            for (j in k - i - 1 until k / 2) {
                res[j] = res[l].also { res[l--] = res[j] }
            }
        }
    }

    return res
}

这里的修改只是将 `maxByOrNull` 替换为 `maxBy` 并添加 `?.size`，其他部分的代码都没有变化。