C - Kalila and Dimna in the Logging Industry 很容易能得到状态转移方程 dp[ i ] = min( dp[ j ] + b[ j ] * a[ i ] ), 然后斜率优化一下. 一直以为炸精度了, 忽然发现手贱把while 写成了if .... #include<bits/stdc++.h> #define LL long long #define fi first #define se second #define mk make_pair #d…
题目:伐木工人用电锯伐木,一共需要砍n棵树,每棵树的高度为a[i],每次砍伐只能砍1单位高度,之后需要对电锯进行充电,费用为当前砍掉的树中最大id的b[id]值.a[1] = 1 , b[n] = 0,a[i]<a[i+1],b[i]>b[i+1].问砍完所有的树的最小费用. 分析:由于b[n] = 0 , 所以很容易弄出一个O(n^2)的状态转移方程. dp[1] = 0; for(int i=2;i<=n;i++){ dp[i] = INF; for(int j=1;j<i;j…
E. Okabe and El Psy Kongroo time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Okabe likes to take walks but knows that spies from the Organization could be anywhere; that's why he wants to k…
A. Magic Numbers 不能出现连续的3个4,以及1.4以外的数字. B. Ping-Pong (Easy Version) 暴力. C. Malek Dance Club 考虑\(x\)二进制每一位1,假设位置为\(p\),则前\(p-1\)位都需要一样,否则之前就计算了贡献,那么后面的位可以任取. D. Psychos in a Line 链表模拟. E. Kalila and Dimna in the Logging Industry 因为\(b_n=0\),所以用最小代价砍倒第…
B. Psychos in a Line Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/problemset/problem/319/B Description There are n psychos standing in a line. Each psycho is assigned a unique integer from 1 to n. At each step every psycho who h…
题目地址:http://codeforces.com/contest/320 第一题:基本题,判断mod 1000,mod 100.,mod 10是不是等于144.14.1,直到为0 代码如下: #include <iostream> #include <cstdio> #include <cstdlib> #include <cmath> #include <cstring> #include <string> #include &…
#include <iostream> #include <vector> #include <algorithm> #include <string> using namespace std; int main(){ long long n; cin >>n; while(n){ if(n%10 == 1) n/=10; else if(n%100 == 14 ) n/=100; else if(n%1000 == 144) n/=1000;…
D. Psychos in a Line time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output There are n psychos standing in a line. Each psycho is assigned a unique integer from 1 to n. At each step every psycho…
A. Magic Numbers time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output A magic number is a number formed by concatenation of numbers 1, 14 and 144. We can use each of these numbers any number of…
传送门:http://codeforces.com/contest/1092/problem/F F. Tree with Maximum Cost time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given a tree consisting exactly of nn vertices. Tree is a…