题目:uva10341-solve it 题目大意:求解给定的方程式解题思路:由于这个方程式在给定的x的范围内是单调递减的.所以能够用二分查找来尝试x的值.这里的 x是要求保留4小数,所以当区间缩小到一定的范围,这时候就是x的解.无解的情况仅仅可能出如今x范围的两端. 代码: #include <stdio.h> #include <stdlib.h> #include <math.h> double p, q, r, s, t, u; const double eps…

二分查找 二分查找又称折半查找,优点是比较次数少,查找速度快,平均性能好:其缺点是要求待查表为有序表,且插入删除困难.因此,折半查找方法适用于不经常变动而查找频繁的有序列表.首先,假设表中元素是按升序排列,将表中间位置记录的关键字与查找关键字比较,如果两者相等,则查找成功:否则利用中间位置记录将表分成前.后两个子表,如果中间位置记录的关键字大于查找关键字,则进一步查找前一子表,否则进一步查找后一子表.重复以上过程,直到找到满足条件的记录,使查找成功,或直到子表不存在为止,此时查找不成功.    …

1514: Packs Time Limit: 10 Sec  Memory Limit: 128 MBSubmit: 61  Solved: 4[Submit][Status][Web Board] Description Give you n packs, each of it has a value v and a weight w. Now you should find some packs, and the total of these value is max, total of…

题意:现在有一个n*m的矩阵A,在A中找一个H*H的正方形,使得其面积最大且该正方形元素的和不大于 limit. 分析:开始以为是DP或者二维RMQ,其实用二分就可以做出来: 在输入时构造元素和矩阵dp[][](即dp[i][j]为从(1,1)到(i,j)的矩形范围元素和);再在(0,min(m,n))范围内二分查找满足条件的最优解H:计算正方形内元素和的方法要掌握; 注意二分时要避免出现L==M而死循环的情况. 代码如下: #include<iostream> #include<cst…

描述 http://poj.org/problem?id=3685 一个n*n的矩阵,(i,j)的值为i*i+100000*i+j*j-100000*j+i*j,求第m小的值. Matrix Time Limit: 6000MS   Memory Limit: 65536K Total Submissions: 5980   Accepted: 1700 Description Given a N × N matrix A, whose element in the i-th row and j…

很多其它请关注我的HEXO博客:http://jasonding1354.github.io/ 简书主页:http://www.jianshu.com/users/2bd9b48f6ea8/latest_articles 二分查找 二分查找算法是一种在有序数组中查找某一特定元素的搜索算法.搜素过程从数组的中间元素開始,假设中间元素正好是要查找的元素,则搜索过程结束:假设某一特定元素大于或者小于中间元素,则在数组大于或小于中间元素的那一半中查找,并且跟開始一样从中间元素開始比較.假设在某一步骤数组…

抄书  (二分查找+贪心) 提示:二分查找一般写成非递归形式 时间复杂度:O(logn) 题目链接:http://acm.hust.edu.cn/vjudge/contest/view.action?cid=85904#problem/B Description   Copying Books Before the invention of book-printing, it was very hard to make a copy of a book. All the contents had…

https://vjudge.net/problem/UVA-1152 题意:给定4个n元素集合A,B,C,D,要求分别从中选取一个元素a,b,c,d,使得a+b+c+d=0.问有多少种取法. 思路:直接暴力枚举的话是会超时的.可以选把a+b的值枚举出来存储,c和d的值也一样并排序,这样就可以在c和d中进行二分查找了. #include<iostream> #include<algorithm> using namespace std; + ; int n; int a[maxn]…

11991 - Easy Problem from Rujia Liu? Time limit: 1.000 seconds Easy Problem from Rujia Liu? Though Rujia Liu usually sets hard problems for contests (for example, regional contests like Xi'an 2006, Beijing 2007 and Wuhan 2009, or UVa OJ contests like…

Valery is a PE teacher at a school in Berland. Soon the students are going to take a test in long jumps, and Valery has lost his favorite ruler! However, there is no reason for disappointment, as Valery has found another ruler, its length is l centim…