#690585 (Go) No.368 LCM of K-products

• 問題: No.368 LCM of K-products
• ユーザー: sgsw
• 提出日時: 2021-08-17 22:31:09
• 言語: Go (1.22.1)
• 結果: AC
• 実行時間: 379 ms / 2,000 ms
• コード長: 1,670 bytes
• コンパイル時間: 11,966 ms
• コンパイル使用メモリ: 232,564 KB
• 実行使用メモリ: 5,888 KB
• 最終ジャッジ日時: 2024-04-19 06:03:47
• 合計ジャッジ時間: 15,513 ms
• ジャッジサーバーID （参考情報）: judge2 / judge5

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	189 ms; 5,248 KB
testcase_01	AC	156 ms; 5,888 KB
testcase_02	AC	263 ms; 5,376 KB
testcase_03	AC	195 ms; 5,376 KB
testcase_04	AC	178 ms; 5,376 KB
testcase_05	AC	379 ms; 5,504 KB
testcase_06	AC	1 ms; 5,376 KB
testcase_07	AC	1 ms; 5,376 KB
testcase_08	AC	2 ms; 5,376 KB
testcase_09	AC	1 ms; 5,376 KB
testcase_10	AC	1 ms; 5,376 KB
testcase_11	AC	1 ms; 5,376 KB
testcase_12	AC	1 ms; 5,376 KB
testcase_13	AC	136 ms; 5,376 KB
testcase_14	AC	213 ms; 5,376 KB
testcase_15	AC	232 ms; 5,632 KB
testcase_16	AC	205 ms; 5,376 KB
testcase_17	AC	170 ms; 5,376 KB
testcase_18	AC	249 ms; 5,632 KB
testcase_19	AC	58 ms; 5,376 KB
testcase_20	AC	154 ms; 5,376 KB
testcase_21	AC	37 ms; 5,376 KB
testcase_22	AC	237 ms; 5,632 KB
testcase_23	AC	1 ms; 5,376 KB
testcase_24	AC	1 ms; 5,376 KB
testcase_25	AC	1 ms; 5,376 KB
testcase_26	AC	1 ms; 5,376 KB
testcase_27	AC	1 ms; 5,376 KB
testcase_28	AC	1 ms; 5,376 KB
testcase_29	AC	2 ms; 5,376 KB
testcase_30	AC	1 ms; 5,376 KB
testcase_31	AC	1 ms; 5,376 KB
testcase_32	AC	1 ms; 5,376 KB
testcase_33	AC	90 ms; 5,376 KB
testcase_34	AC	7 ms; 5,376 KB

ソースコード

package main

import (
	"bufio"
	"fmt"
	"os"
	"sort"
	"strconv"
)

var wg = bufio.NewScanner(os.Stdin)

const (
	inf            = int(1e18)
	initialBufSize = int(1e6)
	maxBufSize     = int(1e6)
	mod            = int(1e9 + 7)
)

var buf []byte = make([]byte, initialBufSize)

func factorize(n int) map[int]int {
	div := n
	retval := make(map[int]int)
	for i := 2; i*i <= n; i++ {
		if div%i == 0 {
			ord := 0
			for div%i == 0 {
				div /= i
				ord++
			}
			retval[i] = ord
		}
	}
	if div > 1 {
		retval[div] = 1
	}
	return retval
}

func main() {
	n, k := nextInt(), nextInt()
	a := make([]int, n)
	for i := 0; i < n; i++ {
		a[i] = nextInt()
	}
	fact_a := make([]map[int]int, n)
	prime_set := make(map[int]bool)
	for i := 0; i < n; i++ {
		fact_a[i] = factorize(a[i])
		for key := range fact_a[i] {
			prime_set[key] = true
		}
	}
	ans := 1
	for p := range prime_set {
		b := make([]int, n)
		for i := 0; i < n; i++ {
			if val, ok := fact_a[i][p]; ok {
				b[i] = val
			}
		}
		sort.Slice(b, func(i, j int) bool {
			return b[i] > b[j]
		})
		ord := 0
		for i := 0; i < k; i++ {
			ord += b[i]
		}
		ans = ans * powMod(p, ord, mod) % mod
	}
	fmt.Printf("%d\n", ans)
}

// greatest common divisor (GCD) via Euclidean algorithm
func GCD(a, b int) int {
	for b != 0 {
		t := b
		b = a % b
		a = t
	}
	return a
}

func powMod(x, n, mod int) int {
	retval := 1
	for mul := x; n > 0; {
		if n&1 == 1 {
			retval = retval * mul % mod
		}
		mul = mul * mul % mod
		n >>= 1
	}
	return retval
}

func init() {
	wg.Split(bufio.ScanWords)
	wg.Buffer(buf, maxBufSize)
}

func nextInt() int {
	wg.Scan()
	i, e := strconv.Atoi(wg.Text())
	if e != nil {
		panic(e)
	}
	return i
}