#689855 (Go) No.1084 積の積

• 問題: No.1084 積の積
• ユーザー: sgsw
• 提出日時: 2021-08-14 13:58:58
• 言語: Go (1.22.1)
• 結果: WA
• 実行時間: -
• コード長: 2,079 bytes
• コンパイル時間: 14,510 ms
• コンパイル使用メモリ: 235,468 KB
• 実行使用メモリ: 7,504 KB
• 最終ジャッジ日時: 2024-10-05 07:10:58
• 合計ジャッジ時間: 16,176 ms
• ジャッジサーバーID （参考情報）: judge1 / judge2

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	1 ms; 6,820 KB
testcase_01	AC	1 ms; 6,820 KB
testcase_02	AC	2 ms; 6,820 KB
testcase_03	AC	1 ms; 6,820 KB
testcase_04	WA	-
testcase_05	RE	-
testcase_06	AC	27 ms; 7,500 KB
testcase_07	RE	-
testcase_08	AC	2 ms; 6,820 KB
testcase_09	RE	-
testcase_10	RE	-
testcase_11	AC	4 ms; 6,816 KB
testcase_12	AC	38 ms; 6,816 KB
testcase_13	AC	78 ms; 7,500 KB
testcase_14	AC	29 ms; 6,816 KB
testcase_15	AC	27 ms; 6,816 KB
testcase_16	AC	89 ms; 7,500 KB
testcase_17	AC	34 ms; 6,820 KB
testcase_18	AC	58 ms; 6,820 KB
testcase_19	AC	78 ms; 7,500 KB
testcase_20	AC	19 ms; 6,816 KB
testcase_21	AC	29 ms; 6,820 KB
testcase_22	AC	23 ms; 6,816 KB
testcase_23	AC	46 ms; 6,816 KB
testcase_24	AC	42 ms; 6,816 KB
testcase_25	AC	77 ms; 7,504 KB
testcase_26	AC	84 ms; 7,500 KB
testcase_27	AC	85 ms; 7,504 KB
testcase_28	AC	85 ms; 7,500 KB
testcase_29	AC	85 ms; 7,500 KB
testcase_30	AC	84 ms; 7,504 KB
testcase_31	AC	85 ms; 7,504 KB

ソースコード

package main

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

var wg = bufio.NewScanner(os.Stdin)

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

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

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

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func modInv(a, modulo int) int {
	b := modulo
	u, v := 1, 0
	for b > 0 {
		t := a / b
		a, b = b, a-t*b
		u, v = v, u-t*v
	}
	u %= modulo
	if u < 0 {
		u += modulo
	}
	return u
}

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

func main() {
	n := nextInt()
	a := make([]int, n)
	for i := 0; i < n; i++ {
		a[i] = nextInt()
	}
	itrs := make([]int, n)
	for product, itr, i := 1, 0, 0; i < n; i++ {
		itr = max(itr, i)
		for itr < n && product*a[itr] <= maxnum {
			product *= a[itr]
			itr++
		}
		itrs[i] = itr
		if itr != i {
			product /= a[i]
		}
	}

	product_a := make([]int, n)
	product_product_a := make([]int, n)

	for i := 0; i < n; i++ {
		if i > 0 {
			product_a[i] = product_a[i-1] * a[i] % mod
		} else {
			product_a[i] = a[i] % mod
		}
	}

	for i := 0; i < n; i++ {
		if i > 0 {
			product_product_a[i] = product_product_a[i-1] * product_a[i] % mod
		} else {
			product_product_a[i] = product_a[i] % mod
		}
	}

	final_ans := 1

	subtask := func(l, r int) int {
		if l > 0 {
			retval := product_product_a[r-1] * modInv(product_product_a[l-1], mod) % mod
			retval = retval * modInv(powMod(product_a[l-1], r-l, mod), mod) % mod
			return retval
		} else {
			retval := product_product_a[r-1] % mod
			return retval
		}
	}
	for l := 0; l < n; l++ {
		if itrs[l] == l {
			continue
		}
		//itrs[l] > l
		final_ans = final_ans * subtask(l, itrs[l]) % mod
	}
	fmt.Printf("%d\n", final_ans)
}