Codeforces Round #539 (Div. 1) A. Sasha and a Bit of Relax description 给一个序列\(a_i\),求有多少长度为偶数的区间\([l,r]\)满足\([l,mid]\)的异或和等于\([mid+1,r]\)的异或和. solution 等价于询问有多少长度为偶数的区间异或和为\(0\). 只需要两个位置的异或前缀和与下标奇偶性相同即可组成一个合法区间. #include<cstdio> #include<algorith…
A. Div. 64 time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Top-model Izabella participates in the competition. She wants to impress judges and show her mathematical skills. Her problem is f…
http://codeforces.com/contest/1129/problem/C #include<bits/stdc++.h> #define fi first #define se second #define INF 0x3f3f3f3f #define fio ios::sync_with_stdio(false);cin.tie(0);cout.tie(0) #define pqueue priority_queue #define NEW(a,b) memset(a,b,s…
A. Be Positive 链接:http://codeforces.com/contest/1130/problem/A 题意: 给一段序列,这段序列每个数都除一个d(−1e3≤d≤1e3)除完后,如果正数的个数可以大于序列长度的一半输出这个d,否则输出0 思路: 直接找正数和负数的个数,正数个数大于一半输出1,负数个数大于一半输出-1,都不大于一半长度输出0就好了 代码: #include<bits/stdc++.h> using namespace std; int main() {…
题目链接:http://www.codeforces.com/problemset/problem/339/A题意:重新组合加法字符串,使得按照1,2,3的顺序进行排列.C++代码: #include <iostream> #include <string> using namespace std; ]; string s, ans = ""; int main() { cin >> s; int len = s.length(); ; i <…
