题目连接: http://acm.hdu.edu.cn/showproblem.php?pid=1506 题目大意: 给出一个数列An,问以Ai为最小值的区间内有多少个元素? 解题思路: 手动模拟一个栈.栈内元素为一个单调不递减序列.当新元素Ai需要进栈,如果栈顶元素大于Ai,弹出栈顶元素,直到栈顶元素不大于Ai,Ai进栈. 这里可以保证i是高为栈顶元素的矩形向后延伸的边界,弹出过程中记录高为Ai的矩阵向前延伸的边界. //#include <bits/stdc++.h> #include &…

                                                                                                   Largest Rectangle in a Histogram       A histogram is a polygon composed of a sequence of rectangles aligned at a common base line. The rectangles have…

题目连接: http://acm.hdu.edu.cn/showproblem.php?pid=1698 题目大意: 有一个钩子有n条棍子组成,棍子有铜银金三种组成,价值分别为1,2,3.为了对付每场战斗需要对组成钩子某个区间的棍子进行调整.问经过q次调整后钩子的总价值是多少? 解题思路: 线段树更新.因为数据范围的问题,每次更新到节点会TLE.用区间更新就会节省很多的时间,对每一个区间来讲,如果这个区间里面的棍子都是相同类型的,就用一个节点变量记录棍子类型,如果区间内棍子是不同类型,则将变量记…

题意:求一个直方图中最大矩形的面积. 很经典的一道问题了吧,可以用单调栈分别求出每个柱子左右两边第一个比它低的柱子(也就相当于求出了和它相连的最后一个比它高的柱子),确定每个柱子的左右边界,每个柱子的高度乘上左右边界的宽度求最大值就行了. 也可以用笛卡尔树上dp的方法搞一搞,即用每个结点权值和所在子树的大小分别表示高度和宽度.(建笛卡尔树的过程也用到了单调栈,作用是维护右链) 单调栈做法: #include<bits/stdc++.h> using namespace std; typedef…

Largest Rectangle in a Histogram Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 19782   Accepted: 6393 Description A histogram is a polygon composed of a sequence of rectangles aligned at a common base line. The rectangles have equal wi…

传送门 Description A histogram is a polygon composed of a sequence of rectangles aligned at a common base line. The rectangles have equal widths but may have different heights. For example, the figure on the left shows the histogram that consists of rec…

Largest Rectangle in a Histogram Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 15831   Accepted: 5121 Description A histogram is a polygon composed of a sequence of rectangles aligned at a common base line. The rectangles have equal wi…

Largest Rectangle in a Histogram Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 29498   Accepted: 9539 Description A histogram is a polygon composed of a sequence of rectangles aligned at a common base line. The rectangles have equal wi…

题目链接:http://poj.org/problem?id=2559 Largest Rectangle in a Histogram Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 24259   Accepted: 7844 Description A histogram is a polygon composed of a sequence of rectangles aligned at a common bas…

题目连接: http://www.lightoj.com/volume_showproblem.php?problem=1084 题目大意: 有n个点在一条以零为起点的坐标轴上,每个点最多可以移动k,问最终能不能把所有点都聚集在大于等于三个点的集合里面,如果能最少需要几个这样的集合? 解题思路: 刚开始看到题目感觉好简单,就开始了sort然后贪心之旅,这就是错误的开始.最后发现这样并不行,然后再Alex的提醒下想用单调队列优化,在我愚昧的理解下竟然写成了bfs,提交竟然ac了,surprise~…