D. Remainders Game 题目连接: http://www.codeforces.com/contest/688/problem/D Description Today Pari and Arya are playing a game called Remainders. Pari chooses two positive integer x and k, and tells Arya k but not x. Arya have to find the value . There…

题目链接: 题目 D. Remainders Game time limit per test 1 second memory limit per test 256 megabytes 问题描述 Today Pari and Arya are playing a game called Remainders. Pari chooses two positive integer x and k, and tells Arya k but not x. Arya have to find the v…

D. Remainders Game time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Today Pari and Arya are playing a game called Remainders. Pari chooses two positive integer x and k, and tells Arya k but…

D. Dividing Kingdom II 题目连接: http://www.codeforces.com/contest/687/problem/D Description Long time ago, there was a great kingdom and it was being ruled by The Great Arya and Pari The Great. These two had some problems about the numbers they like, so…

C. NP-Hard Problem 题目连接: http://www.codeforces.com/contest/688/problem/C Description Recently, Pari and Arya did some research about NP-Hard problems and they found the minimum vertex cover problem very interesting. Suppose the graph G is given. Subs…

B. Lovely Palindromes 题目连接: http://www.codeforces.com/contest/688/problem/B Description Pari has a friend who loves palindrome numbers. A palindrome number is a number that reads the same forward or backward. For example 12321, 100001 and 1 are palin…

A. Opponents 题目连接: http://www.codeforces.com/contest/688/problem/A Description Arya has n opponents in the school. Each day he will fight with all opponents who are present this day. His opponents have some fighting plan that guarantees they will win…

题目链接:http://codeforces.com/problemset/problem/687/A 题意:给出一个n个点m条边的图,分别将每条边连接的两个点放到两个集合中,输出两个集合中的点,若不可能则输出-1: 思路:通过画图我们不难发现,图中没有出现长度为奇数的环则是可行的,反之则是不行的． 对于这点我们可以直接用dfs搜索+染色,对于当前标记为1的点,我们将其所有儿子标记为2, 对于当前标记为2的点,将其所有儿子标记为1,若出现某个节点的标记与其儿子相同,则有长度为奇数的环. 代码:…

D. Dividing Kingdom II   Long time ago, there was a great kingdom and it was being ruled by The Great Arya and Pari The Great. These two had some problems about the numbers they like, so they decided to divide the great kingdom between themselves. Th…

E. The Values You Can Make     Pari wants to buy an expensive chocolate from Arya. She has n coins, the value of the i-th coin is ci. The price of the chocolate is k, so Pari will take a subset of her coins with sum equal to k and give it to Arya. Lo…

每次AB秒出 到了C难度陡然上升...翻译都弄不懂... C 给出一张图 找出两个点的覆盖集(覆盖集是指这图中每条边都有至少一个点在这个点集里面) 并且两个点集没有交集 英文很难看懂...就是二分图的判定 看看这张图是不是二分图 输出两边的点 不是二分图输出-1 坑点是这是special judge 但是题目没说 每个联通块都要进行一次bfs 那些独立点可以不输出也可以随意分配 D 给出k与n个数ci 我们知道一个未知的数x%ci的数 问能不能求出x%k的数 可以利用中国剩余定理来解 如果我们知…

题目链接: 题目 E. The Values You Can Make time limit per test:2 seconds memory limit per test:256 megabytes 问题描述 Pari wants to buy an expensive chocolate from Arya. She has n coins, the value of the i-th coin is ci. The price of the chocolate is k, so Pari…

C. NP-Hard Problem time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Recently, Pari and Arya did some research about NP-Hard problems and they found the minimum vertex cover problem very int…

C. Parity Game 题目连接: http://www.codeforces.com/contest/298/problem/C Description You are fishing with polar bears Alice and Bob. While waiting for the fish to bite, the polar bears get bored. They come up with a game. First Alice and Bob each writes…

B. Strings of Power Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/318/problem/C Description Let us call a pair of integer numbers m-perfect, if at least one number in the pair is greater than or equal to m. Thus, the pair…

B. Long Jumps Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/480/problem/B Description Valery is a PE teacher at a school in Berland. Soon the students are going to take a test in long jumps, and Valery has lost his favorit…

A. Rational Resistance Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/343/problem/A Description Mad scientist Mike is building a time machine in his spare time. To finish the work, he needs a resistor with a certain resista…

D. Directed Roads 题目连接: http://www.codeforces.com/contest/711/problem/D Description ZS the Coder and Chris the Baboon has explored Udayland for quite some time. They realize that it consists of n towns numbered from 1 to n. There are n directed roads…

C. Pythagorean Triples 题目连接: http://www.codeforces.com/contest/707/problem/C Description Katya studies in a fifth grade. Recently her class studied right triangles and the Pythagorean theorem. It appeared, that there are triples of positive integers…

C. Money Transfers 题目连接: http://www.codeforces.com/contest/675/problem/C Description There are n banks in the city where Vasya lives, they are located in a circle, such that any two banks are neighbouring if their indices differ by no more than 1. Al…

C. Polycarpus' Dice Time Limit: 1 Sec  Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/534/problem/C Description Polycarp has n dice d1, d2, ..., dn. The i-th dice shows numbers from 1 to di. Polycarp rolled all the dice and the sum of number…

http://codeforces.com/contest/731/problem/F 注意到一个事实,如果你要找一段区间中(从小到大的),有多少个数是能整除左端点L的,就是[L, R]这样.那么,很明显,把这个区间分段.分成[L, 2 * L - 1],因为这段区间中,都不大于等于L的两倍,这样就使得这段区间的贡献就是sum_number * L了. 就是中间有多少个数,每个数贡献一个L值.然后到枚举[2 * L, 3 * L - 1]这段区间,贡献的值就是sum_number * (2 *…

题目链接: http://codeforces.com/contest/900/problem/D 题意: 给你 \(x\) 和 \(y\),让你求同时满足这两个条件的序列的个数: \(a_1, a_2, ..., a_n (1 ≤ a_i)\). $ 1.$ $gcd(a_1, a_2, ..., a_n) = x $ $ 2.$ \(\sum_{i=1}^{n}a_i = y\) 题解: 可以发现,当\(y\%x!=0\)时,满足条件的序列不存在.让\(f(t)\)表示满足序列和为的 \(t…

链接: https://codeforces.com/contest/1263/problem/A 题意: You have three piles of candies: red, green and blue candies: the first pile contains only red candies and there are r candies in it, the second pile contains only green candies and there are g ca…

链接: https://codeforces.com/contest/1215/problem/A 题意: The final match of the Berland Football Cup has been held recently. The referee has shown n yellow cards throughout the match. At the beginning of the match there were a1 players in the first team…

F. Video Cards time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Little Vlad is fond of popular computer game Bota-2. Recently, the developers announced the new add-on named Bota-3. Of course…

C. Harmony Analysis   The semester is already ending, so Danil made an effort and decided to visit a lesson on harmony analysis to know how does the professor look like, at least. Danil was very bored on this lesson until the teacher gave the group a…

D. "Or" Game time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given n numbers a1, a2, ..., an. You can perform at most k operations. For each operation you can multiply one of…

C. GCD Table time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output The GCD table G of size n × n for an array of positive integers a of length n is defined by formula Let us remind you that the…

D. "Or" Game time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given n numbers a1, a2, ..., an. You can perform at most k operations. For each operation you can multiply one of…