A. Greg and Array Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/295/problem/A Description Greg has an array a = a1, a2, ..., an and m operations. Each operation looks as: li, ri, di, (1 ≤ li ≤ ri ≤ n). To apply operation …

A. Yaroslav and Permutations 值相同的个数不能超过\(\lfloor \frac{n + 1}{2} \rfloor\). B. Yaroslav and Two Strings 答案=总方案数-(S<=W)的方案-(W<=S)的方案+(W==S)的方案. C. Greg and Array 线段树统计每个操作的使用次数,后面就是普通区间加的线段树操作. D. Greg and Graph 反过来操作,即每次加一个点,然后更新距离和. 先计算新点到其他点的最短距离,…

http://codeforces.com/contest/754/problem/D 题意: 给定几组区间,找k组区间,使得它们的公共交集最大. 思路: 在k组区间中,它们的公共交集=k组区间中右端点最小值-k组区间中左端点最大值.如果我们要区间大,那我们应该尽量让左端点小,右端点大. 先对区间按照左端点排序,然后用优先队列处理. 将区间按照左端点从小到大的顺序一一进队列,只需要进右端点即可,如果此时队列内已有k个数,则队首就是这k组区间的最小右端点,而因为左端点是从小到大的顺序进队列的,所以…

Greg's Workout time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Greg is a beginner bodybuilder. Today the gym coach gave him the training plan. All it had was n integers a1, a2, ..., an. Th…

题目链接 Description Yaroslav thinks that two strings s and w, consisting of digits and having length n are non-comparable if there are two numbers, i andj(1 ≤ i, j ≤ n), such that si > wi and sj < wj. Here sign si represents the i-th digit of string s,…

A 直接线段树过的 两遍 貌似大多是标记过的..注意long long #include <iostream> #include <cstdio> #include <cstring> #include <vector> #include <queue> #include <algorithm> using namespace std; #define LL long long #define N 100100 LL s[N<&…

B. Wilbur and Array Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/596/problem/B Description Wilbur the pig is tinkering with arrays again. He has the array a1, a2, ..., an initially consisting of n zeros. At one step, he…

D. One-Dimensional Battle ShipsTime Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/567/problem/D Description Alice and Bob love playing one-dimensional battle ships. They play on the field in the form of a line consisting of n …

题目链接:http://codeforces.com/contest/451/problem/B 思路:首先找下降段的个数,假设下降段是大于等于2的,那么就直接输出no,假设下降段的个数为1,那么就把下降段的起始位置和结束位置记录下来然后进行推断,在进行推断时,有几种特殊情况:(s表示起始位置,e表示结束位置) 1.当e==n&&s!=1时,满足a[n]>a[s-1]输出yes: 2当s==1&&==n时,满足a[1]<a[e+1] 输出yes: 3当s==1&…

http://codeforces.com/contest/1042/problem/D 题意 给一个数组n个元素,求有多少个连续的子序列的和<t (1<=n<=200000,abs(a[i])<=1e9) 思路 将公式转化以下,sum[r]-sum[l-1]<t 变成 sum[r]<sum[l-1]+t 可以考虑遍历每个r,先更新sum[r-1]+t,统计有多少满足条件的sum[l-1],反向树状数组维护即可 实现细节 对于每个r是更新他的sum[r-1] 因为要统计…