B. Fox And Jumping time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Fox Ciel is playing a game. In this game there is an infinite long tape with cells indexed by integers (positive, negativ…

题目链接 题意说的是,有n种卡片,使用第i种卡片可以使当前自己在数轴上的位置移动 l[i],要获得使用第i种卡片的代价是 c[i],求能使自己移动到数轴上任意位置的最小代价,如果不可能则输出-1 当前所拥有的卡片由1->n,逐渐调整map里的值 #include<bits/stdc++.h> using namespace std; ; int n; int c[N],l[N]; map<int,int> dp; int gcd(int a,int b) { return b…

题目链接:http://codeforces.com/problemset/problem/977/F 题意: 给定一个长度为 $n$ 的整数序列 $a[1 \sim n]$,要求你找到一个它最长的一个子序列,该子序列满足单调连续递增. 子序列可以不连续,单调连续递增即例如 $[4,5,6,7]$ 或者 $[6,7,8,9,10]$ 这样的. 题解: $f[i]$ 表示以 $a[i]$ 为结尾的最长连续递增子序列,那么要转移就需要找到 $[1,i-1]$ 这个区间内,某个满足 $a[j] = a…

题目传送门 题意:现在有n座山峰,现在 i-1 与 i 座山峰有 di长的路,现在有m个宠物, 分别在hi座山峰,第ti秒之后可以被带走,现在有p个人,每个人会从1号山峰走到n号山峰,速度1m/s.现在你可以安排好这p个人的出发时间,问所有宠物的等待时间是多少. 题解: 斜率优化DP 我们知道一个人出发之后,该宠物的等待时间就已经决定了. 所以我们可以把每个宠物的0等待时间算出来, 即 A[i] = t[i] - d[h[i]], d为1-h[i]的距离 然后把A[i]排序之后,就可以得到一个出…

You are given an integer array of length nn. You have to choose some subsequence of this array of maximum length such that this subsequence forms a increasing sequence of consecutive integers. In other words the required sequence should be equal to […

题目链接:https://codeforces.com/problemset/problem/570/E 题意: 给出 $n \times m$ 的网格,每一格上有一个小写字母,现在从 $(1,1)$ 位置走到 $(n,m)$ 位置,要求经过路径构成一个回文串. 要求走路方向保证坐标不会减小(即只能往下或者往右走),要求你给出路径方案数目. 题解: 考虑 $f[x_1][y_1][x_2][y_2]$ 表示一端从 $(1,1)$ 出发,走到了 $(x_1,y_1)$,同时另一端从 $(n,m)$…

Levels and Regions 把dp方程列出来, 把所有东西拆成前缀的形式, 就能看出可以斜率优化啦. #include<bits/stdc++.h> #define LL long long #define fi first #define se second #define mk make_pair #define PLL pair<LL, LL> #define PLI pair<LL, int> #define PII pair<int, int&…

Some time ago Slastyona the Sweetmaid decided to open her own bakery! She bought required ingredients and a wonder-oven which can bake several types of cakes, and opened the bakery. Soon the expenses started to overcome the income, so Slastyona decid…

题目链接:http://www.lydsy.com/JudgeOnline/problem.php?id=3357 题意: 给你n个数a[i],让你找出一个最长的是等差数列的子序列. 题解: 表示状态: dp[i][a[j]] = max len 表示当前选了a[i],上一个数是a[j]时,最长的等差数列长度. 找出答案: max dp[i][a[j]] 如何转移: map<int,int> dp[MAX_N]; dp[i][a[j]] = max dp[a[j]][2*a[j] - a[i]…

E. Pashmak and Graph time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Pashmak's homework is a problem about graphs. Although he always tries to do his homework completely, he can't solve thi…