problem1 link 将限制按照$x$排序.那么$[upTo_{i}+1,upTo_{i+1}]$中数字个数为$quantity_{i+1}-quantity_{i}$.然后进行动态规划.$f[i][j]$表示考虑了前$i$个区间的限制,其中偶数的个数为$j$时是否成立. problem2 link 按照如下的规则构造这个图:首先$[1,n]$区间每个节点是单独的一个分量,每次将该区间分为两半.这两半分别需要$k-1$次.最后将这两部分连在一起. problem3 link 如果出现这样一…
problem1 link 倒着想.每次添加一个右括号再添加一个左括号,直到还原.那么每次的右括号的选择范围为当前左括号后面的右括号减去后面已经使用的右括号. problem2 link 令$h(x)=\sum_{i=1}^{x}g(i)$,那么答案为$h(R)-h(L-1)$.对于$h(x)$: (1)如果$x\leq K$,那么$h(x)=0$ (2)否则对于$[K+1,x]$之间的所有偶数来说,对答案的贡献为$even+h(\frac{x}{2})-h(\frac{K}{2})$,其中$e…
Problem Statement You are given the ints perimeter and area. Your task is to find a triangle with the following properties: The coordinates of each vertex are integers between 0 and 3000, inclusive. The perimeter of the triangle must be exactly…
Problem Statement The Happy Letter game is played as follows: At the beginning, several players enter the field. Each player has a lowercase English letter on their back. The game is played in turns. In each turn, you select two players with dif…
