[3주차] : 홍범순 - 4913 페르마의 크리스마스 정리 Gold4 (CBNU-Nnet#60)

홍범순/4913 - 페르마의 크리스마스 정리/main.go

@@ -0,0 +1,82 @@
+package main
+
+import (
+	"fmt"
+)
+
+var ARR_SIZE int = 1000010
+var prime [1000010]bool
+var primesum [1000010]int
+var squaresum [1000010]int
+
+func main() {
+	Init()
+	getPrimes()
+	//debugprint()
+
+	for i := 3; i < ARR_SIZE; i++ {
+		if prime[i] == true {
+			primesum[i] = primesum[i-1] + 1
+		} else {
+			primesum[i] = primesum[i-1]
+		}
+
+		if prime[i] == true && (i%4) == 1 {
+			squaresum[i] = squaresum[i-1] + 1
+		} else {
+			squaresum[i] = squaresum[i-1]
+		}
+	}
+
+	for {
+		var L, U int
+		fmt.Scan(&L, &U)
+
+		x, y := 0, 0
+
+		if L == -1 && U == -1 {
+			return
+		}
+
+		if L >= 1 {
+			x = primesum[U] - primesum[L-1]
+			y = squaresum[U] - squaresum[L-1]
+		} else if L < 1 && U >= 0 {
+			x = primesum[U]
+			y = squaresum[U]
+		} else {
+			x = 0
+			y = 0
+		}
+
+		fmt.Printf("%d %d %d %d\n", L, U, x, y)
+	}
+
+}
+
+func Init() {
+	for i := 2; i < ARR_SIZE; i++ {
+		prime[i] = true
+		primesum[i] = 0
+		squaresum[i] = 0
+	}
+	primesum[2] = 1
+	squaresum[2] = 1
+}
+
+func getPrimes() {
+	prime[1] = false
+	for i := 2; i*i < ARR_SIZE; i++ {
+		if prime[i] == true {
+			for j := i * i; j < ARR_SIZE; j += i {
+				prime[j] = false
+			}
+		}
+	}
+}
+
+func debugprint() {
+	for i := 0; i < 50; i++ {
+		fmt.Printf("%d %d \n", i, prime[i])
+	}
+}