[链接] 我是链接,点我呀:) [题意] 题意 [题解] 第一个人攻击一次需要1/x秒 第二个人攻击一次需要1/y秒 这两个数字显然都是小数. 我们可以二分最后用了多少时间来攻击. 显然这个是有单调性的,攻击时间越多的话,攻击的次数也就越多. 假设二分出来攻击的时间是mid 那么攻击的次数就是 mid/(1/x) + mid/(1/y) 但是这样显然二分出来的也是一个小数. 我们完全没有办法根据二分出来的东西判断它到底是谁的倍数. 因此我们可以这样. 我们把第一个人攻击一次和第二个人攻击一次所需…

time limit per test1 second memory limit per test256 megabytes inputstandard input outputstandard output Vanya is doing his maths homework. He has an expression of form , where x1, x2, -, xn are digits from 1 to 9, and sign represents either a plus '…

time limit per test4 seconds memory limit per test512 megabytes inputstandard input outputstandard output Vanya got bored and he painted n distinct points on the plane. After that he connected all the points pairwise and saw that as a result many tri…

time limit per test1 second memory limit per test256 megabytes inputstandard input outputstandard output Vanya has a scales for weighing loads and weights of masses w0,?w1,?w2,?-,?w100 grams where w is some integer not less than 2 (exactly one weight…

time limit per test1 second memory limit per test256 megabytes inputstandard input outputstandard output Vanya got an important task - he should enumerate books in the library and label each book with its number. Each of the n books should be assigne…

time limit per test2 seconds memory limit per test256 megabytes inputstandard input outputstandard output Vanya has a table consisting of 100 rows, each row contains 100 cells. The rows are numbered by integers from 1 to 100 from bottom to top, the c…

time limit per test1.5 seconds memory limit per test256 megabytes inputstandard input outputstandard output Vanya is in the palace that can be represented as a grid n × m. Each room contains a single chest, an the room located in the i-th row and j-t…

[codeforces 415D]Mashmokh and ACM 题意:美丽数列定义:对于数列中的每一个i都满足:arr[i+1]%arr[i]==0 输入n,k(1<=n,k<=2000),问满足[数列长度是k && 数列中每一个元素arr[i]在1~n之间 && 数列中元素可以重复]的数列有多少个?结果对10^9+7取余 解题思路:dp[i][j]表示长度是j,最后一位是i的种数 if(kk%i==0) dp[kk][j+1]+=dp[i][j] #inc…

time limit per test4 seconds memory limit per test256 megabytes inputstandard input outputstandard output Anton is playing a very interesting computer game, but now he is stuck at one of the levels. To pass to the next level he has to prepare n potio…

time limit per test2 seconds memory limit per test256 megabytes inputstandard input outputstandard output Due to the increase in the number of students of Berland State University it was decided to equip a new computer room. You were given the task o…