problem1 link 分别计算可以得到(a,b)的有哪些二元组,以及可以得到(c,d)的有哪些二元组.然后在公共的二元组中找到和最大的即可. problem2 link 设最后的排序为$r=[2,4,1,0,5,3]$.初始时$2=4=1=0=5=3$.从后向前考虑每一个使用的技能.最后一个使用的技能一定是将某些等于符号变成了大于符号.倒数第二次使用的技能一定是将目前的某些等于号变成大于号(或者没有改变).依次类推直到所有的符号都变成了大于号.假设存在一个正确的序列可以满足要求,将其作为当…
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…
