POJ 3320 Jessica's Reading Problem 题意:一本书P页,第i页有ai知识点,问你至少从某一处开始连续要翻多少页才能复习完所有的知识点,不能跨页翻. 思路:<挑战程序设计>上的尺取法的经典例题,set用来求出所有不重复知识点的个数,map用来计算是否有新出现的的知识点. 1.左端点s,右端点t,目前复习的知识点num初始化为0: 2.只要有t < P,num < n,且出现新的知识点counts[a[t++]]++==0,num++: 3.如果num…

1.POJ 3320 2.链接:http://poj.org/problem?id=3320 3.总结:尺取法,Hash,map标记 看书复习,p页书,一页有一个知识点,连续看求最少多少页看完所有知识点 必须说,STL够屌.. #include<iostream> #include<cstring> #include<cmath> #include<queue> #include<algorithm> #include<cstdio>…

题目传送门 /* 尺取法:先求出不同知识点的总个数tot,然后以获得知识点的个数作为界限, 更新最小值 */ #include <cstdio> #include <cmath> #include <cstring> #include <algorithm> #include <set> #include <map> using namespace std; ; const int INF = 0x3f3f3f3f; int a[MA…

A - Jessica's Reading Problem POJ - 3320 Jessica's a very lovely girl wooed by lots of boys. Recently she has a problem. The final exam is coming, yet she has spent little time on it. If she wants to pass it, she has to master all ideas included in a…

题目链接: http://poj.org/problem?id=3320 题目大意:一本书有P页,每页有个知识点,知识点可以重复.问至少连续读几页,使得覆盖全部知识点. 解题思路: 知识点是有重复的,因此需要统计不重复元素个数,而且需要记录重复个数. 最好能及时O(1)反馈不重复的个数.那么毫无疑问,得使用Hash. 推荐使用map,既能Hash,也能记录对于每个key的个数. 尺取的思路: ①不停扩展R,并把扫过知识点丢到map里,直到map的size符合要求. ②更新结果. ②L++,map…

http://poj.org/problem?id=3320 题意:给出一串数字,要求包含所有数字的最短长度. 思路: 哈希一直不是很会用,这道题也是参考了别人的代码,想了很久. #include<iostream> #include<algorithm> #include<string> #include<cstring> using namespace std; ; int n; int len; //开散列法,也就是用链表来存储,所以下面的len是从P…

地址 http://poj.org/problem?id=3320 解答 使用双指针 在指针范围内是否达到要求 若不足要求则从右进行拓展  若满足要求则从左缩减区域 代码如下  正确性调整了几次 然后被输入卡TLE卡了很久都没意识到......... #include <iostream> #include <map> #include <set> #include <algorithm> #include <assert.h> #include…

Description Jessica's a very lovely girl wooed by lots of boys. Recently she has a problem. The final exam is coming, yet she has spent little time on it. If she wants to pass it, she has to master all ideas included in a very thick text book. The au…

Jessica's Reading Problem Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 6496   Accepted: 1998 Description Jessica's a very lovely girl wooed by lots of boys. Recently she has a problem. The final exam is coming, yet she has spent littl…

传送门:Problem 3320 参考资料: [1]:挑战程序设计竞赛 题意: 一本书有 P 页,每页都有个知识点a[i],知识点可能重复,求包含所有知识点的最少的页数. 题解: 相关说明: 设以a[start]开始的最初包含所有知识点的最少连续子序列为a[start,....,end]; mymap[ a[i] ] : 知识点 a[i] 在当前最少连续子序列中出现的次数. (1):求出所需复习的知识点总个数. (2):求出最先包含所有知识点的最少页数a[start,........,end].…

Jessica's Reading Problem Description Jessica's a very lovely girl wooed by lots of boys. Recently she has a problem. The final exam is coming, yet she has spent little time on it. If she wants to pass it, she has to master all ideas included in a ve…

jessica's Reading PJroblem Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 9134   Accepted: 2951 Description Jessica's a very lovely girl wooed by lots of boys. Recently she has a problem. The final exam is coming, yet she has spent litt…

Jessica's Reading Problem Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 17562   Accepted: 6099 Description Jessica's a very lovely girl wooed by lots of boys. Recently she has a problem. The final exam is coming, yet she has spent litt…

Jessica's Reading Problem 题目大意:Jessica期末考试临时抱佛脚想读一本书把知识点掌握,但是知识点很多,而且很多都是重复的,她想读最少的连续的页数把知识点全部掌握(知识点都在书上,每一页都是一个知识点) 这一题可以用3061的游标卡尺法,我们可以先数数书上倒到底有多少个知识点,因为知识点都是序数,我们可以用二分法直接找到O(PlogP),这里可以采用set模板直接偷懒了,然后我们就可以用游标卡尺法了,因为所有知识点都要出现一次,所以我们统计新的知识点的出现就好了,最…

Jessica's Reading Problem Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 6001   Accepted: 1800 Description Jessica's a very lovely girl wooed by lots of boys. Recently she has a problem. The final exam is coming, yet she has spent littl…

题 题意 P个数,求最短的一段包含P个数里所有出现过的数的区间. 分析 尺取法,边读边记录每个数出现次数num[d[i]],和不同数字个数n个. 尺取时,l和r 代表区间两边,每次r++时,d[r]即r的出现次数+1,d[l]即l的出现次数大于1时,左边可以短一点,d[l]--,l++,直到d[l]出现次数为1,当不同数达到n个,且区间更小,就更新答案. 代码 #include <cstdio> #include <map> using namespace std; map <…

Description Jessica's a very lovely girl wooed by lots of boys. Recently she has a problem. The final exam is coming, yet she has spent little time on it. If she wants to pass it, she has to master all ideas included in a very thick text book. The au…

Description Jessica's a very lovely girl wooed by lots of boys. Recently she has a problem. The final exam is coming, yet she has spent little time on it. If she wants to pass it, she has to master all ideas included in a very thick text book. The au…

Subsequence Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 13955   Accepted: 5896 Description A sequence of N positive integers (10 < N < 100 000), each of them less than or equal 10000, and a positive integer S (S < 100 000 000) ar…

题意:n页书,然后n个数表示各个知识点ai,然后,输出最小覆盖的页数. #include<iostream> #include<cstdio> #include<set> #include<map> using namespace std; ; int num[maxn]; int main(){ int n; set<int>ss; map<int, int>mm; scanf("%d", &n); ;…

Jessica's a very lovely girl wooed by lots of boys. Recently she has a problem. The final exam is coming, yet she has spent little time on it. If she wants to pass it, she has to master all ideas included in a very thick text book. The author of that…

题意:给定一个序列,求一个最短区间,使得这个区间包含所有的种类数. 析:最近刚做了几个滑动窗口的题,这个很明显也是,肯定不能暴力啊,时间承受不了啊,所以 我们使用滑动窗口来解决,要算出所有的种数,我用set来计算的,当然也可以用别的, 由于要记录种类数,所以使用map来记录,删除和查找方便,说到这,这不就是水题了么. 代码如下: #include <iostream> #include <cstdio> #include <algorithm> #include <…

Jessica's Reading Problem Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 7467   Accepted: 2369 Description Jessica's a very lovely girl wooed by lots of boys. Recently she has a problem. The final exam is coming, yet she has spent littl…

Description Jessica's a very lovely girl wooed by lots of boys. Recently she has a problem. The final exam is coming, yet she has spent little time on it. If she wants to pass it, she has to master all ideas included in a very thick text book. The au…

题目: 解法:定义左索引和右索引 1.先让右索引往右移,直到得到所有知识点为止: 2.然后让左索引向右移,直到刚刚能够得到所有知识点: 3.用右索引减去左索引更新答案,因为这是满足要求的子串. 4.不断重复1,2,3.直到搜索到最后,不论怎样都获得不了所有的知识点时跳出. 代码: #include <iostream> #include <algorithm> #include <stdio.h> #include <vector> #include <…

尺取法(two point)的思想不难,简单来说就是以下三步: 1.对r point在满足题意的情况下不断向右延伸 2.对l point前移一步 3.  回到1 two point 对连续区间的问题求解有其独到之处 复杂度为0(n) 很实用的 #include<iostream> #include<map> #include<set> #include<vector> #include<cstdio> #define inf 1000002 us…

题目链接: 传送门 They Are Everywhere time limit per test:2 second     memory limit per test:256 megabytes Description Sergei B., the young coach of Pokemons, has found the big house which consists of n flats ordered in a row from left to right. It is possib…

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前言 很多人到现在为止都总是问我算法该怎么学啊,数据结构好难啊怎么的,学习难度被莫名的夸大了,其实不然.对于一个学计算机相关专业的人都知道,数据结构是大学的一门必修课,数据结构与算法是基础,却常常容易被忽视,行业越浮躁,变化越快,开发平台越便捷,高级 API 越多,基本功的重要性就越容易被忽视.即使能意识到基础薄弱,肯下定决心腾出几个月时间恶补基本功不是件容易的事,尤其是参加工作后,琐事繁多,一时热血下定的决心能坚持一周都实属不易.数据结构与算法的学习难度经常被夸大,不少人甚至谈算法色变,尤其无…

A sequence of N positive integers (10 < N < 100 000), each of them less than or equal 10000, and a positive integer S (S < 100 000 000) are given. Write a program to find the minimal length of the subsequence of consecutive elements of the sequen…