题目链接 Alyona and Spreadsheet 记a[i][j]为读入的矩阵,c[i][j]为满足a[i][j],a[i - 1][j], a[i - 2][j],......,a[k][j]不上升的k的最小值. d[i]为max(c[i][j]) (1 <= j <= m) 那么对于每次询问l,r,若d[r] <= l,那么就符合,反之不符. 因为这里只说名了1 <= nm <= 100000,所以二维数组两个维的大小不确定. 数据可能有n=1, m=100000,…

C. Alyona and Spreadsheet time limit per test:1 second memory limit per test:256 megabytes input:standard input output:standard output During the lesson small girl Alyona works with one famous spreadsheet computer program and learns how to edit table…

题目链接:http://codeforces.com/problemset/problem/777/C 题意: 给定 $n \times m$ 的一个数字表格,给定 $k$ 次查询,要你回答是否存在某一列 $j$,其对应于询问区间 $[l,r]$ 的 $a[l][j], a[l+1][j], \cdots, a[r][j]$ 这个序列,是否为非递减的. 题解: 考虑 $f[i][j]$ 表示只考虑第 $j$ 列的情况下,以 $a[i][j]$ 为末尾的单调不减序列的最长长度,这个很容易求出来.…

题目链接:http://codeforces.com/problemset/problem/777/C 题目意思:给出一个 n * m 的矩阵,然后问 [l, r] 行之间是否存在至少一列是非递减序列 解析: (1)原输入:    ——> (2)统计第 i 行里第 j 列 的最长非递减序列数 ——> (3)每列非递减序列在第 i 行的最长值 然后有两种方法:  二维数组 和 一维数组的处理.个人偏向一维数组 方法 一 (一维数组) #include <iostream> #incl…

Alyona and Spreadsheet 这就是一道思维的题,谈不上算法什么的,但我当时就是不会,直到别人告诉了我,我才懂了的.唉 为什么总是这么弱呢? [题目链接]Alyona and Spreadsheet &题意: 给一n*m的表,之后给T个询问,每个询问是r1和r2,问从r1行到r2行(包括这2行)是否至少有一列是非递减的? &题解: 可以把给的n*m表处理一下,处理成b[i][j]数组,存的是第j列递增开始的位置是第几行. 这样,只有b中第r2行最小的小于r1就行了,否则就是…

题目链接:http://codeforces.com/contest/777/problem/C C. Alyona and Spreadsheet time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output During the lesson small girl Alyona works with one famous spreadsh…

C.Alyona and Spreadsheet During the lesson small girl Alyona works with one famous spreadsheet computer program and learns how to edit tables. Now she has a table filled with integers. The table consists of n rows and mcolumns. By ai, j we will denot…

C. Alyona and Spreadsheet time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output During the lesson small girl Alyona works with one famous spreadsheet computer program and learns how to edit table…

题目描述: Alyona and a tree time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Alyona has a tree with n vertices. The root of the tree is the vertex 1. In each vertex Alyona wrote an positive int…

http://codeforces.com/problemset/problem/777/C 题意:给一个矩阵,对于每一列定义一个子序列使得mp[i][j] >= mp[i-1][j],即如果满足这样的情况,那么序列长度+1.给出q个询问,问[l,r]的行区间内是否有一个这样的子序列. 思路:用两个数组,第一个数组row记录每一列到第i行的序列长度,第二个数组ans记录每一行到第j列最长的序列长度.然后询问的时候判断ans[r]是否有区间长度大就可以了. 5 41 2 3 53 1 3 24 5…

During the lesson small girl Alyona works with one famous spreadsheet computer program and learns how to edit tables. Now she has a table filled with integers. The table consists of n rows and m columns. By \(a_{i, j}\) we will denote the integer loc…

[题目链接]:http://codeforces.com/contest/777/problem/C [题意] 给你n行m列的矩阵: 然后给你k个询问[l,r]; 问你在第l到第r行,是否存在一个列,这一列的第l到第r行是升序的; 是输出YES,否则输出NO [题解] /* 对于每一列; 从小到大枚举行; 对于第i行; 看看从第i个元素能有序多长,dp[i]; 然后对于j (j∈[i..i+dp[i]-1]),dp[j] = dp[i]-(i-j); 然后i = i+dp[i]; 记录下第i行,…

C. Alyona and mex Problem Description: Alyona's mother wants to present an array of n non-negative integers to Alyona. The array should be special. Alyona is a capricious girl so after she gets the array, she inspects m of its subarrays. Subarray is…

题意:给你n行m列的数组,和k次的询问,问从l行到r行是否存在一个非递增的列 思路:看到这道题的数据量我们就知道直接暴力不可取,所以我们采用了预处理的方法,我们记录下来每一行的最长的非递减的列的开头的哪个行,比如num[i]=k;表示到第i行的最长的非递减的列是从第k行开始的,在每一次的询问中我们只需要比较num[r]的值与l的值就可以了: 代码: #include <cstdio> #include <cmath> #include <iostream> #inclu…

对询问按右端点排序,对每一列递推出包含当前行的单调不下降串最多向前延伸多少. 用multiset维护,取个最小值,看是否小于等于该询问的左端点. #include<cstdio> #include<vector> #include<algorithm> #include<set> using namespace std; multiset<int>S; #define INF 2147483647 struct Data { int l,r,p;…

C. Alyona and mex time limit per test: 2 seconds memory limit per test: 256 megabytes input: standard input output: standard output Alyona's mother wants to present an array of n non-negative integers to Alyona. The array should be special. Alyona is…

A. Alyona and copybooks time limit per test: 1 second memory limit per test: 256 megabytes input: standard input output: standard output Little girl Alyona is in a shop to buy some copybooks for school. She study four subjects so she wants to have eq…

题目链接 Alyona and a tree 比较考验我思维的一道好题. 首先,做一遍DFS预处理出$t[i][j]$和$d[i][j]$.$t[i][j]$表示从第$i$个节点到离他第$2^{j}$近的祖先,$d[i][j]$表示从$i$开始到$t[i][j]$的路径上的路径权值总和. 在第一次DFS的同时,对节点$x$进行定位(结果为$dist(x, y)<=a(y)$)的离$x$最远的$x$的某个祖先,然后进行$O(1)$的差分. 第一次DFS完成后,做第二次DFS统计答案(统计差分后的结…

题目链接:http://codeforces.com/problemset/problem/682/C 题意:如果点v在点u的子树上且dist(u,v)>a[v]则u和其整个子树都将被删去,求被删去的点数. 思路:1为根节点,从1开始DFS遍历,记录距离dis为到祖宗节点的最大距离. #include<bits/stdc++.h> using namespace std; typedef long long ll; const int N=1e5+5; int a[N],num[N],a…

Police Recruits Time Limit: 1000MS   Memory Limit: 262144KB   64bit IO Format: %I64d & %I64u Submit Status Description The police department of your city has just started its journey. Initially, they don’t have any manpower. So, they started hiring n…

Alyona and Strings 题目链接: http://acm.hust.edu.cn/vjudge/contest/121333#problem/D Description After returned from forest, Alyona started reading a book. She noticed strings s and t, lengths of which are n and m respectively. As usual, reading bored Aly…

Alyona and the Tree 题目链接: http://acm.hust.edu.cn/vjudge/contest/121333#problem/C Description Alyona decided to go on a diet and went to the forest to get some apples. There she unexpectedly found a magic rooted tree with root in the vertex 1, every v…

Alyona and Mex 题目链接: http://acm.hust.edu.cn/vjudge/contest/121333#problem/B Description Someone gave Alyona an array containing n positive integers a1, a2, ..., an. In one operation, Alyona can choose any element of the array and decrease it, i.e. re…

Alyona and Numbers 题目链接: http://acm.hust.edu.cn/vjudge/contest/121333#problem/A Description After finishing eating her bun, Alyona came up with two integers n and m. She decided to write down two columns of integers - the first column containing inte…

Alyona and Triangles 题目连接: http://acm.hust.edu.cn/vjudge/contest/121333#problem/J Description You are given n points with integer coordinates on the plane. Points are given in a way such that there is no triangle, formed by any three of these n point…

codeforces 895B XK Segments 题目大意: 寻找符合要求的\((i,j)\)对,有:\[a_i \le a_j \] 同时存在\(k\),且\(k\)能够被\(x\)整除,\(k\)满足:\[a_i \le k \le a_j\] 思路: 整体数组排序,对于当前\(a_i\)寻找符合条件的\(a_j\)的最大值和最小值 有:\[(a_i-1)/x+k=a_j/x\] 所以可以通过二分查找获得,这里我寻找\(((a_i-1)/x+k)*x\)为下界,\(((a_i-1)/x…

codeforces 893D Credit Card 题目大意: 有一张信用卡可以使用,每天白天都可以去给卡充钱.到了晚上,进入银行对卡的操作时间,操作有三种: 1.\(a_i>0\) 银行会给卡充入\(a_i\)元 2.\(a_i<0\) 银行从卡中扣除\(a_i\)元 3.\(a_i=0\) 银行对你的卡进行评估,违背了规则就无权再使用此卡 规则1:卡内的余额不得超过\(d\)元 规则2:当\(a_i=0\)时,卡内的余额不能是负数 现在问为了维持信用的平衡,最少去银行几次.(去一次,充…

C. Nice Garland time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output You have a garland consisting of nn lamps. Each lamp is colored red, green or blue. The color of the ii-th lamp is sisi ('R',…

Alyona and towers 这个题写起来真的要人命... 我们发现一个区间被加上一个d的时候, 内部的结构是不变的, 改变的只是左端点右端点的值, 这样就能区间合并了. 如果用差分的话会简单一些, 就变成了求前一段是负数,后一段是正数的最长段多长. #include<bits/stdc++.h> #define LL long long #define fi first #define se second #define mk make_pair #define PLL pair<…

http://codeforces.com/problemset/problem/848/B 给定一个二维坐标系,点从横轴或纵轴垂直于发射的坐标轴射入(0,0)-(w,h)的矩形空间.给出点发射的坐标轴,位置,延迟时间,发生碰撞则交换方向.求最后每个点的射出位置. 首先我们观察能得出两个结论,1. 类似蚂蚁爬树枝的问题,相遇只会交换方向,所以最后的射出点集只会因为碰撞而改变动点与射出点的对应关系,而不会增加减少射出点集.2.我们根据其射入位置和延迟时间可以计算出一个值v=pos-time,只有这…