solve(BOJ): G5_1456_거의_소수_kt

src/boj/G5_1456_거의_소수.kt

@@ -0,0 +1,45 @@
+package boj
+
+import kotlin.math.pow
+import kotlin.math.sqrt
+
+class BOJ1456() {
+
+
+    fun solve() {
+        val (a, b) = readln().split(" ").map { it.toLong() }
+
+        val MAX = sqrt(b.toDouble()).toInt()
+        val isPrime = BooleanArray(MAX + 1) { true }
+        var count = 0
+        isPrime[0] = false
+        isPrime[1] = false
+
+        for (i in 2..MAX / 2) {
+            if (!isPrime[i]) continue
+            var mul = 2
+            while (true) {
+                isPrime[i * mul] = false
+                mul++
+                if (i * mul > MAX) break
+            }
+        }
+
+        for (i in 2..MAX) {
+            if (!isPrime[i]) continue
+            var exp = 2
+            while (true) {
+                val num = i.toDouble().pow(exp)
+                if (num >= a && num <= b) count++
+                else if (num > b) break
+                exp++
+            }
+        }
+
+        println(count)
+    }
+}
+
+fun main() {
+    BOJ1456().solve()
+}