题意:给定 n 种不同的钞票,然后用q个询问,问你用最多k张,最多两种不同的钞票能不能组成一个值. 析:首先如果要求的值小点,就可以用DP,但是太大了,所以我们考虑一共最多有n * k种钞票,如果每次都挨着遍历,时间肯定受不了, 所以我们可以枚举其中一种,然后再用二分查找快速查找另一种,然后不断更新答案. 代码如下: #pragma comment(linker, "/STACK:1024000000,1024000000") #include <cstdio> #incl…
我先采用了智障解法(n * n枚举...刚开始把n看成1000了还以为能过) 理所当然的t了,不过我怀疑优化一下能过?(感觉数据不太行的亚子 然后就是O(n * k * k)的解法,看到好多人快乐二分,其实完全用不到,建一个10000000的数组就ok了(我刚开始还以为会MLE 不过有几个地方要注意一下 1.要判断是不是在范围内,不然会出现查询的时候越界,快乐re的情况 2.要判断是不是>0,同理,而且负数取模会有你意想不到的结果 #include <cstdio> #include &…
VK Cup 2015 - Round 1 (unofficial online mirror, Div. 1 only)E. The Art of Dealing with ATM Time Limit: 2 Sec  Memory Limit: 256 MBSubmit: xxx  Solved: 2xx 题目连接 http://codeforces.com/contest/529/problem/E Description ATMs of a well-known bank of a sm…
题目大意 ATM取款机有n种不同的钱币kind[i],每次取款允许吐出不超过k张钱币,且钱币的种类数不能超过2(一开始没理解2的意思),现在有q次取款,钱数为ques,问ATM能否凑出这样的钱,若能的话吐出的钱币数最少是多少. n <= 5000, k <= 20, q <= 20, kind[i] <= 10 ^ 7, ques <= 2 * 10 ^ 8. 题解: 用两种钱找零可以写成a * x + b * y = ques,其中x和y是两种钱币.a和b是两种钱币分别用的…
ATMs of a well-known bank of a small country are arranged so that they can not give any amount of money requested by the user. Due to the limited size of the bill dispenser (the device that is directly giving money from an ATM) and some peculiarities…
题目链接: http://codeforces.com/contest/672/problem/C 题意: 公园里有两个人一个垃圾桶和n个瓶子,现在这两个人需要把所有的瓶子扔进垃圾桶,给出人,垃圾桶,瓶子的坐标,问两个人需要走的最短距离和. 题解: 首先必须要有一个人先去检一个瓶子,然后走到垃圾桶,这个可以枚举,接下来就是考虑另一个人是也捡一个瓶子然后走到垃圾桶(这个可以预处理出最优的,和次优的,因为如果最优的那个刚好被第一个人拿走了,那就拿次优的)还是在原地不动,接下去就是固定的了,求剩下的所…
C. Watering Flowers 题目连接: http://www.codeforces.com/contest/617/problem/C Descriptionww.co A flowerbed has many flowers and two fountains. You can adjust the water pressure and set any values r1(r1 ≥ 0) and r2(r2 ≥ 0), giving the distances at which t…
B. HDD is Outdated Technology 题目连接: http://www.codeforces.com/contest/612/problem/B Description HDD hard drives group data by sectors. All files are split to fragments and each of them are written in some sector of hard drive. Note the fragments can…
题目链接:http://codeforces.com/problemset/problem/686/C 给你n和m,问你有多少对(a, b) 满足0<=a <n 且 0 <=b < m 且a的7进制和n-1的7进制位数相同 且b的7进制和m-1的7进制位数相同,还有a和b的7进制上的每位上的数各不相同. 看懂题目,就很简单了,先判断a和b的7进制位数是否超过7,不超过的话就dfs暴力枚举计算就可以了. //#pragma comment(linker, "/STACK:1…
B. Queries on a String Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/598/problem/B Description You are given a string s and should process m queries. Each query is described by two 1-based indices li, ri and integer ki. I…
B. Biridian Forest Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/329/problem/B Description You're a mikemon breeder currently in the middle of your journey to become a mikemon master. Your current obstacle is go through t…
D. Valid Sets Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/486/problem/D Description As you know, an undirected connected graph with n nodes and n - 1 edges is called a tree. You are given an integer d and a tree consist…
B. Once Again... Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/582/problem/B Description You are given an array of positive integers a1, a2, ..., an × T of length n × T. We know that for any i > n it is true that ai = ai -…
C. GCD Table Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/583/problem/C Description 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 greatest c…
D. Three Logos Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/581/problem/D Description Three companies decided to order a billboard with pictures of their logos. A billboard is a big square board. A logo of each company is…
B. Two Sets Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/468/problem/B Description Little X has n distinct integers: p1, p2, ..., pn. He wants to divide all of them into two sets A and B. The following two conditions must…
A. Robbers' watch 题目连接: http://www.codeforces.com/contest/685/problem/A Description Robbers, who attacked the Gerda's cab, are very successful in covering from the kingdom police. To make the goal of catching them even harder, they use their own watc…
A. Help Farmer 题目连接: http://www.codeforces.com/contest/142/problem/A Description Once upon a time in the Kingdom of Far Far Away lived Sam the Farmer. Sam had a cow named Dawn and he was deeply attached to her. Sam would spend the whole summer stocki…
C. Old Berland Language 题目连接: http://www.codeforces.com/contest/37/problem/C Description Berland scientists know that the Old Berland language had exactly n words. Those words had lengths of l1, l2, ..., ln letters. Every word consisted of two letter…
A. Recycling Bottles 题目连接: http://www.codeforces.com/contest/671/problem/A Description It was recycling day in Kekoland. To celebrate it Adil and Bera went to Central Perk where they can take bottles from the ground and put them into a recycling bin.…
B. World Tour 题目连接: http://www.codeforces.com/contest/666/problem/B Description A famous sculptor Cicasso goes to a world tour! Well, it is not actually a world-wide. But not everyone should have the opportunity to see works of sculptor, shouldn't he…
C. Removing Columns time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given an n × m rectangular table consisting of lower case English letters. In one operation you can completely r…
A. Karen and Morning time limit per test 2 seconds memory limit per test 512 megabytes input standard input output standard output Karen is getting ready for a new school day! It is currently hh:mm, given in a 24-hour format. As you know, Karen loves…
B. Obsession with Robots 题目连接: http://www.codeforces.com/contest/8/problem/B Description The whole world got obsessed with robots,and to keep pace with the progress, great Berland's programmer Draude decided to build his own robot. He was working har…
A. Combination Lock Time Limit: 1 Sec  Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/540/problem/A Description Scrooge McDuck keeps his most treasured savings in a home safe with a combination lock. Each time he wants to put there the treas…
题目链接:codeforces 797 E. Array Queries   题意:给你一个长度为n的数组a,和q个询问,每次询问为(p,k),相应的把p转换为p+a[p]+k,直到p > n为止,求每次询问要转换的次数. 题解:纯暴力会TLE,所以在k为根号100000范围内dp打表 dp[i][j]表示初始p为i, k为j,需要转换几次可以大于n. 状态转移方程:dp[i][j] = dp[i+a[i]+j] + 1 #include <cstdio> #include <al…
D. Image Preview 题目连接: http://www.codeforces.com/contest/651/problem/D Description Vasya's telephone contains n photos. Photo number 1 is currently opened on the phone. It is allowed to move left and right to the adjacent photo by swiping finger over…
B. Beautiful Paintings 题目连接: http://www.codeforces.com/contest/651/problem/B Description There are n pictures delivered for the new exhibition. The i-th painting has beauty ai. We know that a visitor becomes happy every time he passes from a painting…
A. Minimum Difficulty time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Mike is trying rock climbing but he is awful at it. There are n holds on the wall, i-th hold is at height ai off the g…
Codeforces 1108E2 E2. Array and Segments (Hard version) Description: The only difference between easy and hard versions is a number of elements in the array. You are given an array \(a\) consisting of \(n\) integers. The value of the \(i\)-th element…