CF1654D.Potion Brewing Class
提高+/省选-
通过率:0%
时间限制:3.00s
内存限制:256MB
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题目描述
Alice's potion making professor gave the following assignment to his students: brew a potion using n ingredients, such that the proportion of ingredient i in the final potion is ri>0 (and r1+r2+⋯+rn=1).
He forgot the recipe, and now all he remembers is a set of n−1 facts of the form, "ingredients i and j should have a ratio of x to y" (i.e., if ai and aj are the amounts of ingredient i and j in the potion respectively, then it must hold ai/aj=x/y), where x and y are positive integers. However, it is guaranteed that the set of facts he remembers is sufficient to uniquely determine the original values ri.
He decided that he will allow the students to pass the class as long as they submit a potion which satisfies all of the n−1 requirements (there may be many such satisfactory potions), and contains a positive integer amount of each ingredient.
Find the minimum total amount of ingredients needed to make a potion which passes the class. As the result can be very large, you should print the answer modulo 998244353.
爱丽丝的魔药学教授给学生们布置了如下作业:使用 n 种原料配制一种魔药,使得第 i 种原料在最终魔药中所占比例为 ri>0(且满足 r1+r2+⋯+rn=1)。
他遗忘了原始配方,如今仅记得一组共 n−1 条事实,每条形如:“原料 i 与原料 j 的用量之比应为 x:y”(即若魔药中原料 i 与原料 j 的用量分别为 ai 和 aj,则必须满足 ai/aj=x/y),其中 x 和 y 均为正整数。但题目保证他所记住的这组事实足以唯一确定原始比例值 ri。
他决定:只要学生提交的魔药满足全部 n−1 条约束条件(满足条件的魔药可能有多个),且每种原料的用量均为正整数,则视为通过课程。
请找出满足上述要求的魔药所需的最小总原料用量。由于答案可能非常大,请将结果对 998244353 取模后输出。
输入格式
The first line contains a single integer t (1≤t≤104) — the number of test cases.
The first line of each test case contains a single integer n (2≤n≤2⋅105).
Each of the next n−1 lines contains four integers i,j,x,y (1≤i,j≤n, i=j, 1≤x,y≤n) — ingredients i and j should have a ratio of x to y. It is guaranteed that the set of facts is sufficient to uniquely determine the original values ri.
It is also guaranteed that the sum of n for all test cases does not exceed 2⋅105.
第一行包含一个整数 t(1≤t≤104)—— 表示测试用例的数量。
每个测试用例的第一行包含一个整数 n(2≤n≤2⋅105)。
接下来的 n−1 行中,每行包含四个整数 i,j,x,y(1≤i,j≤n,i=j,1≤x,y≤n)—— 表示原料 i 与原料 j 的比例应为 x:y。题目保证所给条件足以唯一确定原始值 ri。
同时保证所有测试用例的 n 值之和不超过 2⋅105。
输出格式
For each test case, print the minimum total amount of ingredients needed to make a potion which passes the class, modulo 998244353.
对于每个测试用例,输出制作一剂能通过课程的药水所需的最少总原料量,对 998244353 取模。
输入输出样例
输入#1
3 4 3 2 3 4 1 2 4 3 1 4 2 4 8 5 4 2 3 6 4 5 4 1 3 5 2 6 8 2 1 3 5 3 4 3 2 2 5 6 7 4 3 17 8 7 4 16 9 17 4 5 5 14 13 12 11 1 17 14 6 13 8 9 2 11 3 11 4 17 7 2 17 16 8 6 15 5 1 14 16 7 1 10 12 17 13 10 11 16 7 2 10 11 6 4 13 17 14 6 3 11 15 8 15 6 12 8
输出#1
69 359 573672453
说明/提示
In the first test case, the minimum total amount of ingredients is 69. In fact, the amounts of ingredients 1,2,3,4 of a valid potion are 16,12,9,32, respectively. The potion is valid because
- Ingredients 3 and 2 have a ratio of 9:12=3:4;
- Ingredients 1 and 2 have a ratio of 16:12=4:3;
- Ingredients 1 and 4 have a ratio of 16:32=2:4.
In the second test case, the amounts of ingredients 1,2,3,4,5,6,7,8 in the potion that minimizes the total amount of ingredients are 60,60,24,48,32,60,45,30.
在第一个测试用例中,所需原料的最小总量为 69。事实上,一种合法药水所需的原料 1,2,3,4 的量分别为 16,12,9,32。该药水是合法的,因为:
- 原料 3 与原料 2 的比例为 9:12=3:4;
- 原料 1 与原料 2 的比例为 16:12=4:3;
- 原料 1 与原料 4 的比例为 16:32=2:4。
在第二个测试用例中,使原料总用量最小的药水中,原料 1,2,3,4,5,6,7,8 的用量分别为 60,60,24,48,32,60,45,30。
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