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…

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…

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…

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…

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…

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>…

B - Bound Found POJ - 2566 Signals of most probably extra-terrestrial origin have been received and digitalized by The Aeronautic and Space Administration (that must be going through a defiant phase: "But I want to use feet, not meters!"). Each…

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 <…

Bound Found Time Limit: 5000MS   Memory Limit: 65536K Total Submissions: 1651   Accepted: 544   Special Judge Description Signals of most probably extra-terrestrial origin have been received and digitalized by The Aeronautic and Space Administration…

Graveyard Design Time Limit: 10000MS Memory Limit: 64000K Total Submissions: 8504 Accepted: 2126 Case Time Limit: 2000MS Description King George has recently decided that he would like to have a new design for the royal graveyard. The graveyard must…