题目链接:http://codeforces.com/problemset/problem/616/E 题意很简单就不说了. 因为n % x = n - n / x * x 所以答案就等于 n * m - (n/1*1 + n/2*2 ... n/m*m) 在根号n复杂度枚举x,注意一点当m>n时,后面一段加起来就等于0,就不用再枚举了. 中间一段x1 ~ x2 的n/x可能相等,所以相等的一段等差数列求和. //#pragma comment(linker, "/STACK:102400…

E. Sum of Remainders 题目连接: http://www.codeforces.com/contest/616/problem/E Description The only line contains two integers n, m (1 ≤ n, m ≤ 1013) - the parameters of the sum. input The only line contains two integers n, m (1 ≤ n, m ≤ 1013) - the para…

Educational Codeforces Round 63 (Rated for Div. 2) D. Beautiful Array time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given an array aa consisting of nn integers. Beauty of array i…

题目链接:http://codeforces.com/contest/616/problem/E 题目大意:给定整数n,m(1≤n,m≤1013), 求(n mod 1 + n mod 2 + ... + n mod m)的值(mod Pt = 1e9 + 7). 思路:这题一看是看觉得题意简洁,通过人数不多一定是一道用到各种定理的碉堡数论题.后来仔细想了一下发现是乱搞… 首先通过观察数据范围,结合数论题的复杂度传统考虑O(√n)算法. 把n拆解,可以任意写成很多种n = px + r 的形式,…

D. Optimal Number Permutation 题目连接: http://www.codeforces.com/contest/622/problem/D Description You have array a that contains all integers from 1 to n twice. You can arbitrary permute any numbers in a. Let number i be in positions xi, yi (xi < yi) i…

A. USB Flash Drives 题目连接: http://www.codeforces.com/contest/609/problem/A Description Sean is trying to save a large file to a USB flash drive. He has n USB flash drives with capacities equal to a1, a2, ..., an megabytes. The file size is equal to m…

A. The Text Splitting 题目连接: http://www.codeforces.com/contest/612/problem/A Description You are given the string s of length n and the numbers p, q. Split the string s to pieces of length p and q. For example, the string "Hello" for p = 2, q = 3…

B. The Best Gift 题目连接: http://www.codeforces.com/contest/609/problem/B Description Emily's birthday is next week and Jack has decided to buy a present for her. He knows she loves books so he goes to the local bookshop, where there are n books on sale…

A. Fashion in Berland 题目连接: http://www.codeforces.com/contest/691/problem/A Description According to rules of the Berland fashion, a jacket should be fastened by all the buttons except only one, but not necessarily it should be the last one. Also if…

D. Iterated Linear Function 题目连接: http://www.codeforces.com/contest/678/problem/D Description Consider a linear function f(x) = Ax + B. Let's define g(0)(x) = x and g(n)(x) = f(g(n - 1)(x)) for n > 0. For the given integer values A, B, n and x find t…

C. Joty and Chocolate 题目连接: http://www.codeforces.com/contest/678/problem/C Description Little Joty has got a task to do. She has a line of n tiles indexed from 1 to n. She has to paint them in a strange pattern. An unpainted tile should be painted R…

B. The Same Calendar 题目连接: http://www.codeforces.com/contest/678/problem/B Description The girl Taylor has a beautiful calendar for the year y. In the calendar all days are given with their days of week: Monday, Tuesday, Wednesday, Thursday, Friday,…

A. Johny Likes Numbers 题目连接: http://www.codeforces.com/contest/678/problem/A Description Johny likes numbers n and k very much. Now Johny wants to find the smallest integer x greater than n, so it is divisible by the number k. Input The only line con…

A. Buses Between Cities 题目连接: http://www.codeforces.com/contest/665/problem/A Description Buses run between the cities A and B, the first one is at 05:00 AM and the last one departs not later than at 11:59 PM. A bus from the city A departs every a mi…

B. Seating On Bus 题目连接: http://www.codeforces.com/contest/660/problem/B Description Consider 2n rows of the seats in a bus. n rows of the seats on the left and n rows of the seats on the right. Each row can be filled by two people. So the total capac…

B. Balanced Substring time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output You are given a string s consisting only of characters 0 and 1. A substring [l, r] of s is a string slsl + 1sl + 2... s…

题意:给出一个字符串s, 可以从左往右拿走s的字符, 至少要到s的第几个位置才能拼成t 思路:用二维数组记录前缀,然后二分即可. #include<bits/stdc++.h> using namespace std; #define inf 5000000 #define N 210050 ]; ]; string s; string str; int n; bool slove(int id) { ; i<; i++) ) return false; return true; } i…

C. The Number Of Good Substrings Problem Description: You are given a binary string s (recall that a string is binary if each character is either 0 or 1).Let f(t) be the decimal representation of integer t written in binary form (possibly with leadin…

Problem Description: You are fighting with Zmei Gorynich — a ferocious monster from Slavic myths, a huge dragon-like reptile with multiple heads!Initially Zmei Gorynich has x heads. You can deal n types of blows. If you deal a blow of the i-th type,…

Problem Description: You play your favourite game yet another time. You chose the character you didn't play before. It has str points of strength and int points of intelligence. Also, at start, the character has exp free experience points you can inv…

D. Credit Card Recenlty Luba got a credit card and started to use it. Let's consider n consecutive days Luba uses the card. She starts with 0 money on her account. In the evening of i-th day a transaction ai occurs. If ai > 0, then ai bourles are dep…

链接 直接用数组记录每个字母的个数即可 #include<bits/stdc++.h> using namespace std; int a[26] = {0}; int b[26] = {0}; int judge() { //cout<<"111"<<endl; for (int i = 0; i < 26; ++i) { if (a[i]!=b[i]) { return 0; } } return 1; } int main() { //…

题意: 给你n个关卡,每个关卡有一个怪物,怪物的攻击力为a[i],你有n个英雄,每个英雄有一个攻击力,和疲劳值,只要英雄的攻击力比怪物的高就算打过了,同时疲劳减一,一天只能出战一个英雄,一个英雄可以打好几关(只要在疲劳范围内),打不过的话英雄就结束今天的挑战,转到第二天.问最少需要出战多少英雄才能通过所有关卡. 思路:先用一个数组.跑出相同忍耐值时,攻击力越大.然后·跑出这个数组的后缀pre数组,pre数组的含义是:忍耐值一定,攻击力最大.然后通过O(n)的复杂度跑·怪物的数组.当怪物的a[i]…

慢慢来. 题目册 题目 A B C D E F G 状态 √ √ √ √ × ∅ ∅ //√,×,∅ 想法 A. Prime Subtraction res tp A 题意:给定\(x,y(x>y)\),问能否将\(x-y\)拆成任意多个质数之和 1.任意大于\(1\)的整数\(k\)都可以用\(2\)与\(3\)的线性表示 证: 若\(k\)是偶数,显然: 若\(k\)是奇数,则\(k\)可以表示成\(k = 3 + 2*k'\),显然: 毕. #include<bits/stdc++.h&…

B. The Modcrab Vova is again playing some computer game, now an RPG. In the game Vova's character received a quest: to slay the fearsome monster called Modcrab. After two hours of playing the game Vova has tracked the monster and analyzed its tactics…

C. Rumor Vova promised himself that he would never play computer games... But recently Firestorm — a well-known game developing company — published their newest game, World of Farcraft, and it became really popular. Of course, Vova started playing it…

B. Beautiful Divisors Recently Luba learned about a special kind of numbers that she calls beautiful numbers. The number is called beautiful iff its binary representation consists of k + 1 consecutive ones, and then k consecutive zeroes. Some example…

A. Chess For Three Alex, Bob and Carl will soon participate in a team chess tournament. Since they are all in the same team, they have decided to practise really hard before the tournament. But it's a bit difficult for them because chess is a game fo…

A. Remove a Progression 签到题,易知删去的为奇数,剩下的是正偶数数列. #include<iostream> using namespace std; int T; int n,x; int main(){ cin>>T; while(T--){ cin>>n>>x; cout<<x * 2<<endl; } return 0; } B. Yet Another Crosses Problem n*m存在上界,…

Educational Codeforces Round 53 E. Segment Sum 题意: 问[L,R]区间内有多少个数满足:其由不超过k种数字构成. 思路: 数位DP裸题,也比较好想.由于没考虑到前导0,卡了很久.但最惨的是,由于每次求和的时候需要用到10的pos次幂,我是用提前算好的10的最高次幂,然后每次除以10往下传参.但我手贱取模了,导致每次除以10之后答案就不同余了,这个NC细节错误卡了我一小时才发现. 代码: #include<iostream> #include<…