AtCoder problem 017

C++ solution:


Python solution: # でつoO(YOU PLAY WITH THE CARDS YOU'RE DEALT..)
import sys
def main():
    input = sys.stdin.readline
    N, M = map(int, input().split())
    S = [[] for _ in range(N)]
    T = [[] for _ in range(N)]
    E = []
    for i in range(M):
        s, t = map(lambda x: int(x) - 1, input().split())
        S[s].append(i)
        T[t].append(i)
        E.append((s, t))
    st = SegmentTree(N, f=lambda a, b: a + b)
    ans = 0
    for n in range(N):
        for i in T[n]:
            s, t = E[i]
            st.modify_at(s, -1)
        for i in T[n]:
            s, t = E[i]
            ans += st.query(s + 1, t)
        st.modify_at(n, len(S[n]))
    print(ans)

class SegmentTree:
    __slots__ = ('__n', '__d', '__f', '__e')

    def __init__(self, n=None, f=max, identity_factory=int, initial_values=None):
        assert(n or initial_values)
        size = n if n else len(initial_values)
        d = [identity_factory() for _ in range(2 * size + 1)]
        self.__n, self.__d, self.__f, self.__e = size, d, f, identity_factory
        if initial_values:
            for i, v in enumerate(initial_values): d[size + i] = v
            for i in range(size - 1, 0, -1): d[i] = f(d[i << 1], d[i << 1 | 1])

    def __repr__(self) -> str:
        n = self.__n
        return str([self.get_at(i) for i in range(n)])

    def get_at(self, index):
        return self.__d[index + self.__n]

    def set_at(self, index, new_value):
        i, d, f = index + self.__n, self.__d, self.__f
        if d[i] == new_value: return
        d[i], i = new_value, i >> 1
        while i: d[i], i = f(d[i << 1], d[i << 1 | 1]), i >> 1

    def modify_at(self, index, value):
        self.set_at(index, self.__f(self.__d[index + self.__n], value))

    def query(self, from_inclusive, to_exclusive):
        ans = self.__e()
        if to_exclusive <= from_inclusive: return ans
        l, r, d, f = from_inclusive + self.__n, to_exclusive + self.__n, self.__d, self.__f
        while l < r:
            if l & 1: ans, l = f(ans, d[l]), l + 1
            if r & 1: ans, r = f(d[r - 1], ans), r - 1
            l, r = l >> 1, r >> 1
        return ans

    def query_all(self):
        return self.__d[1]

    def bisect_left(self, func, from_inclusive=None, to_exclusive=None):
        '''func()がTrueになるもっとも左のindexを探す
        '''
        n, f, d, v = self.__n, self.__f, self.__d, self.__e()
        l = (from_inclusive if from_inclusive else 0) + n
        r = (to_exclusive if to_exclusive else n) + n
        h = 0
        while l < r:
            if l & 1:
                nv = f(v, d[l])
                if func(nv): return self.__single_bisect_left(func, l, v)
                v, l = nv, l + 1
            l, r, h = l >> 1, r >> 1, h + 1
        if r == 0: return n
        for i in range(h, 0, -1):
            if ((r + 1) << i <= n + n):
                nv = f(v, d[r])
                if func(nv): return self.__single_bisect_left(func, r, v)
                v, r = nv, r + 1
            r <<= 1
        return n

    def __single_bisect_left(self, func, root, left_val):
        n, f, d = self.__n, self.__f, self.__d
        i, v = root, left_val
        while i < n:
            i <<= 1
            nv = f(v, d[i])
            if not func(nv): i, v = i + 1, nv
        return i - n

if __name__ == '__main__':
    main()




Kuin solution: func main()
	var n: int :: cui@inputInt()
	var m: int :: cui@inputInt()
	var lr: []Lr :: #[m]Lr
	for i(0, m - 1)
		var l: int :: cui@inputInt() - 1
		var r: int :: cui@inputInt() - 1
		do lr[i] :: (#Lr).init(l, r)
	end for
	do lr.sort()
	
	var bitL: @Bit :: (#@Bit).init(n)
	var bitR: @Bit :: (#@Bit).init(n)
	var ans: int :: 0
	for i(0, m - 1)
		var l: int :: lr[i].l
		var r: int :: lr[i].r
		if(l <> 0)
			do ans :+ bitL.sum(l - 1)
			do ans :- bitR.sum(l)
		end if
		do bitL.add(l, 1)
		do bitR.add(r, 1)
	end for
	
	do cui@print("\{ans}\n")
	
	class Lr()
		+var l: int
		+var r: int
		+func init(l: int, r: int): Lr
			do me.l :: l
			do me.r :: r
			ret me
		end func
		+*func cmp(t: kuin@Class): int
			if(me.r < (t $ Lr).r)
				ret - 1
			elif(me.r > (t $ Lr).r)
				ret 1
			elif(me.l > (t $ Lr).l)
				; 今回の方法の場合、
				; rが等しいときは、lが大きい順にしないと、
				; 数え上げ時に重複しやすい。
				ret - 1
			end if
			ret 0
		end func
	end class
end func

class Bit()
	var n: int
	var data: []int
	+func init(n: int): Bit
		do me.n :: n
		do me.data :: #[n + 1]int
		ret me
	end func
	+func add(i: int, v: int)
		var x: int :: i + 1
		while(x <= me.n)
			do me.data[x] :+ v
			do x :+ (x $ bit64).and(((-x) $ bit64)) $ int
		end while
	end func
	+func sum(i: int): int
		var x: int :: i + 1
		var res: int :: 0
		while(x > 0)
			do res :+ me.data[x]
			do x :- (x $ bit64).and(((-x) $ bit64)) $ int
		end while
		ret res
	end func
end class