Description In the ``Four Color Map Theorem" was proven with the assistance of a computer. This theorem states that every map can be colored using only four colors, in such a way that no region is colored using the same color as a neighbor region. He…

Description Background Professor Hopper is researching the sexual behavior of a rare species of bugs. He assumes that they feature two different genders and that they only interact with bugs of the opposite gender. In his experiment, individual bugs…

要点 会发现本质上棋盘分成了若干个独立集,本集合内的点放不放棋子并不影响其他集合内的 集合的划分方式就是满棋盘跳马步直到全跳过了,然后每个集合就分成两队,我们选人多的那队放棋子,人少那队当禁区 const int maxn = 1e3 + 5; const int nx[] = {-2, -2, -1, -1, 1, 1, 2, 2}; const int ny[] = {-1, 1, -2, 2, -2, 2, -1, 1}; int n, m; bool grid[maxn][maxn];…

要点 将边作为染色,如果交叉则异色 #include <cstdio> #include <algorithm> #include <functional> using namespace std; int n, m; int a[101], b[101], c[101]; int main() { scanf("%d %d", &n, &m); for (int i = 1; i <= m; i++) { scanf(&quo…

发现奇环不可行,偶环可行,考虑二分图.然后染色,方向全都从一种指向另一种就可以了,随意. ; int n, m, color[maxn]; vector<int> vc[maxn]; vector<P> e; void dfs(int cur, int co) { color[cur] = co; for (auto i : vc[cur]) { if (!color[i]) { dfs(i, - co); } else if (color[i] == color[cur]) {…

Palindromic characteristics of string s with length |s| is a sequence of |s| integers, where k-th number is the total number of non-empty substrings of s which are k-palindromes. A string is 1-palindrome if and only if it reads the same backward as f…

题目 给定N个点和M条边,从点1出发,到达点T.寻找路径上边的个数小于等于K的路径,求出所有满足条件的路径中最长边长度的最小值. 题目链接:二分     最小化最大值,考虑采用二分搜索.对所有的边长进行排序,二分,对每次选择的边长,判断是否存在一条路径满足路径上所有的边长度均小于等于该边长,且路径中的边的个数小于等于K.     在判断路径是否存在的时候,使用BFS搜索,因为BFS用于寻找最短(边的个数最少)路径. 实现 #include<stdio.h> #include<string…

题意,给你一个l,和一个地图,让你从起点走到终点,使得路程刚好等于l. 你可以选择一个系数,把纵向的地图拉伸或收缩,比如你选择系数0.5,也就是说现在上下走一步消耗0.5的距离,如果选择系数3,也就是说上下一步消耗3的距离. 左右不能改变. Hint中提示了答案在0--10之间,其实就透露出了二分的思想. 我们对系数P进行二分,对每一个系数P进行一次bfs,如果可以在小于等于l的步数内找到解,则增加下界,否则减小上界. 由于上下和左右的消耗值不相同,所以我们采用A*算法,设估价值为当前点到目标点…

题目:CodeForces - 363D 题意:给定n个学生,其中每个学生都有各自的私己钱,并且自己的私己钱只能用在自己买自行车,不能给别人. 给定m个自行车,每个自行车都有一个价格. 给定公有财产a.    然后求出这些学生能买自行车的最大数量,并且求当买下最大自行车数量时,总体花费私己钱的最少的钱. 我先来说以下二分搜索模板: //右值点不能取到的情况 int binary_search(vector<int>& nums,int left,int right, int targe…

In one of the games Arkady is fond of the game process happens on a rectangular field. In the game process Arkady can buy extensions for his field, each extension enlarges one of the field sizes in a particular number of times. Formally, there are n…