B. Filya and Homework 题目连接: http://codeforces.com/contest/714/problem/B Description Today, hedgehog Filya went to school for the very first time! Teacher gave him a homework which Filya was unable to complete without your help. Filya is given an arra…

题目链接:http://codeforces.com/problemset/problem/714/B 题目大意: 第一行输入一个n,第二行输入n个数,求是否能找出一个数x,使得n个数中的部分数加上x或部分数减去x ,n个数相等. 例如:5 1 3 3 2 1 输出: YES Init: x=1 情况,第一个数和最后一个数+x,第二三个数减去x ,则这n个数都为2(相等),故输出“YES” 解题思路: 对于刚才举的例子 可知 n个数只有三个元素 1 2 3 只要使得 2-1==3-2 即可满足条…

A: 题目大意: 在一个multiset中要求支持3种操作: 1.增加一个数 2.删去一个数 3.给出一个01序列,问multiset中有多少这样的数,把它的十进制表示中的奇数改成1,偶数改成0后和给出的01序列相等(比较时如果长度不等各自用0补齐) 题解: 1.我的做法是用Trie数来存储,先将所有数用0补齐成长度为18位,然后就是Trie的操作了. 2.官方题解中更好的做法是,直接将每个数的十进制表示中的奇数改成1,偶数改成0,比如12345,然后把它看成二进制数10101,还原成十进制是2…

B. Filya and Homework time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Today, hedgehog Filya went to school for the very first time! Teacher gave him a homework which Filya was unable to com…

A. Meeting of Old Friends time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Today an outstanding event is going to happen in the forest — hedgehog Filya will come to his old fried Sonya! Sony…

D. Animals and Puzzle 题目连接: http://codeforces.com/contest/713/problem/D Description Owl Sonya gave a huge lake puzzle of size n × m to hedgehog Filya as a birthday present. Friends immediately started to assemble the puzzle, but some parts of it turn…

D. Searching Rectangles 题目连接: http://codeforces.com/contest/714/problem/D Description Filya just learned new geometry object - rectangle. He is given a field consisting of n × n unit cells. Rows are numbered from bottom to top with integer from 1 to…

A. Meeting of Old Friends 题目连接: http://codeforces.com/contest/714/problem/A Description Today an outstanding event is going to happen in the forest - hedgehog Filya will come to his old fried Sonya! Sonya is an owl and she sleeps during the day and s…

题目链接:http://codeforces.com/contest/714/problem/B 题意:给定一个长度为N的初始序列,然后问是否能找到一个值x,然后使得序列的每个元素+x/-x/不变,最后把序列变成各个元素都相等(序列每个元素只能进行操作一次) 思路:因为每个元素只能操作一次,而且操作的值只有一个值x.那么就可以发现当序列中存在3个以上的互不相等的数时一定不能构造要求的序列. 当序列存在3个一下的互补相同的数时,一定能构造要求的序列.现在要考虑的是刚刚有3个互不相同的序列时,把序列…

题目链接:http://codeforces.com/contest/714/problem/A 题意:有两个人A,B 给定A的时间区间[L1,R1], B的时间区间[L2,R2],然后在正好K分钟的时候A小时一分钟,即K这一分钟A不在.现在问A和B在时间上能相遇多久. 思路:相遇的区间是[max(L1,L2),min(R1,R2)],然后判断K是否在这个区间里就好了. 还有可能相遇的区间大小为负数即A和B不相遇 #define _CRT_SECURE_NO_DEPRECATE #include…