problem1 link 肯定存在相邻两堆满足不会存在任何操作在这两堆之间进行.然后就成为一条链,那么只需要维护链的前缀和即可判断当前堆和前一堆之间需要多少次操作. problem2 link 对于两个数字$x,y,x<y$,如果$y$不是$x$的倍数,那么一定有$lcm(x,y)+gcd(x,y)>x+y$.不妨假设$x=p_{1}^{a_{1}}p_{2}^{b_{1}},y=p_{1}^{a_{2}}p_{2}^{b_{2}}$,其中$p_{1},p_{2}$是两个不同的素数且$a_{…
problem1 link 倒着想.每次添加一个右括号再添加一个左括号,直到还原.那么每次的右括号的选择范围为当前左括号后面的右括号减去后面已经使用的右括号. problem2 link 令$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…
