题目链接:http://codeforces.com/problemset/problem/788/B B. Weird journey time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Little boy Igor wants to become a traveller. At first, he decided to vi…
D. Weird journey time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Little boy Igor wants to become a traveller. At first, he decided to visit all the cities of his motherland — Uzhlyandia. I…
考虑这个二元组中有一者是自环,则必然合法. 考虑这两条边都不是自环,如果它们不相邻,则不合法,否则合法. 坑的情况是,如果它是一张完整的图+一些离散的点,则会有解,不要因为图不连通,就误判成无解. #include<cstdio> #include<iostream> using namespace std; typedef long long ll; ll ans; int n,m,zihuan; int v[2000010],next[2000010],first[200001…
人傻不会B 写了C正解结果因为数组开小最后RE了 疯狂掉分 AC:A Rank:392 Rating: 2191-92->2099 A. Functions again 题目大意:给定一个长度为n的数组,求最大的,其中1<=l<r<=n.(n<=10^5) 思路:按左端点所在位置的奇偶性分开计算即可. #include<cstdio> #include<algorithm> using namespace std; #define ll long lo…
来自FallDream的博客,未经允许,请勿转载,谢谢. ------------------------------------------------------ A.Anastasia and pebbles 你有两个口袋,每种口袋最多只能装k个物品,有n种物品,每种物品有ai个,两种不同的物品不能混在一起,问最少要装多少次. 题解:............. #include<iostream> #include<cstdio> #include<cmath>…
图论 D. Weird journey time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Little boy Igor wants to become a traveller. At first, he decided to visit all the cities of his motherland — Uzhlyandia…
暴搜 #include<cstdio> #include<algorithm> using namespace std; int n,K,Div=1,a[21],m,ans=100; bool vis[21]; void calc(int now) { int t=0; bool flag=0; for(int i=m;i>=1;--i) if(!vis[i]) { if((!flag) && a[i]==0) return; t=t*10+a[i]; fla…
[Link]:http://codeforces.com/contest/839/problem/C [Description] 给一棵树,每当你到一个点x的时候,你进入x的另外一每一个出度的概率都是相同的(但不能到你之前到过的点); 问你从1出发走过的路径的期望长度; [Solution] 从1出发,看看到达某个点的概率是多少; 到了叶子节点的时候,概率乘距离累加到答案上. [NumberOf WA] 0 [Reviw] [Code] #include <bits/stdc++.h> usi…
A. Anastasia and pebbles time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Anastasia loves going for a walk in Central Uzhlyandian Park. But she became uninterested in simple walking, so she…
考虑枚举每个子串开头的位置,然后答案转化成询问这个位置之后 哪个位置的前缀和 - 这位置的前缀和 最大(当然是已经把绝对值和正负的情况处理好了,可以发现按奇偶,这个序列只有两种情况),只需要预处理这两个序列的前缀和,以及这两个前缀和序列的后缀max即可. #include<cstdio> #include<iostream> using namespace std; typedef long long ll; int Abs(int x){ return x<0 ? (-x)…