A946.The Great Revegetation--Silver
普及+/提高
通过率:0%
时间限制:1.00s
内存限制:128MB
题目描述
A lengthy drought has left Farmer John's N pastures devoid of grass.
However, with the rainy season arriving soon, the time has come to
"revegetate". In Farmer John's shed, he has two buckets, each with a different
type of grass seed. He wants to plant grass in each of his N pastures,
choosing exactly one type of grass to plant in each.
Being a dairy farmer, Farmer John wants to make sure he manages the somewhat
particular dietary needs of his M cows. Each of his M cows has two
favorite pastures. Some of his cows have a dietary restriction that they
should only eat one type of grass consistently --- Farmer John therefore wants
to make sure the same type of grass is planted in the two favorite fields of
any such cow. Other cows have a very different dietary restriction, requiring
them to eat different types of grass. For those cows, Farmer John of course
wants to make sure their two favorite fields contain different grass types.
Please help Farmer John determine the number of different ways he can plant
grass in his N pastures.
输入格式
The first line of input contains N (2≤N≤105) and M (1≤M≤105). Each of the next M lines contains a character that is either
'S' or 'D', followed by two integers in the range 1…N, describing the
pair of pastures that are the two favorites for one of Farmer John's cows. If
the character is 'S', this line represents a cow that needs the same type of
grass in its two favorite pastures. If the character is 'D', the line
represents a cow that needs different grass types.
输出格式
Output the number of ways Farmer John can plant grass in his N pastures.
Please write your answer in binary.
输入输出样例
输入#1
3 2 S 1 2 D 3 2
输出#1
10