zoukankan      html  css  js  c++  java
  • uva 10004

     

      Bicoloring 

    In 1976 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.

    Here you are asked to solve a simpler similar problem. You have to decide whether a given arbitrary connected graph can be bicolored. That is, if one can assign colors (from a palette of two) to the nodes in such a way that no two adjacent nodes have the same color. To simplify the problem you can assume:

    • no node will have an edge to itself.
    • the graph is nondirected. That is, if a node a is said to be connected to a node b, then you must assume that b is connected to a.
    • the graph will be strongly connected. That is, there will be at least one path from any node to any other node.

    Input 

    The input consists of several test cases. Each test case starts with a line containing the number n ( 1 < n < 200) of different nodes. The second line contains the number of edges l. After this, l lines will follow, each containing two numbers that specify an edge between the two nodes that they represent. A node in the graph will be labeled using a number a ( $0 le a < n$).

    An input with n = 0 will mark the end of the input and is not to be processed.

    Output 

    You have to decide whether the input graph can be bicolored or not, and print it as shown below.

    Sample Input 

    3
    3
    0 1
    1 2
    2 0
    9
    8
    0 1
    0 2
    0 3
    0 4
    0 5
    0 6
    0 7
    0 8
    0
    

    Sample Output 

    NOT BICOLORABLE.
    BICOLORABLE.
    #include <iostream>
    #include <stack>
    #include <cstring>
    #include <cstdio>
    #include <string>
    #include <algorithm>
    #include <queue>
    #include <set>
    #include <map>
    #include <fstream>
    #include <stack>
    #include <list>
    #include <sstream>
    #include <cmath>
    
    using namespace std;
    
    #define ms(arr, val) memset(arr, val, sizeof(arr))
    #define mc(dest, src) memcpy(dest, src, sizeof(src))
    #define N 205
    #define INF 0x3fffffff
    #define vint vector<int>
    #define setint set<int>
    #define mint map<int, int>
    #define lint list<int>
    #define sch stack<char>
    #define qch queue<char>
    #define sint stack<int>
    #define qint queue<int>
    
    int cnt, ans, front[N];
    int tag[N];
    struct node
    {
        int next, to;
    }edge[40005];
    
    void addedge(int s, int e)
    {
        edge[cnt].next = front[s];
        front[s] = cnt;
        edge[cnt++].to = e;
    }
    
    void dfs(int i)
    {
        for (int s = front[i]; s != -1; s = edge[s].next)
        {
            if (tag[edge[s].to])
            {
                if (tag[edge[s].to] == tag[i])
                {
                    ans = 0;
                    return;
                }
            }
            else
            {
                tag[edge[s].to] = -tag[i];
                dfs(edge[s].to);
            }
        }
    }
    
    int main()
    {
        //freopen("1.cpp", "r", stdin);
        int n, l, s, e;
        while (scanf("%d", &n), n)
        {
            scanf("%d", &l);
            ms(front, -1);
            ms(tag, 0);
            ans = tag[0] = 1;
            cnt = 0;
            while (l--)
            {
                scanf("%d%d", &s, &e);
                addedge(s, e);
                addedge(e, s);
            }
            dfs(0);
            puts((ans ? "BICOLORABLE." : "NOT BICOLORABLE."));
        }
    
        return 0;
    }
  • 相关阅读:
    WinCC的电子签名与审计追踪 2.0
    如何在VB脚本中Ping IP
    如何在WinCC中管理Windows账户
    配置SQL Server维护计划-定时备份
    修改SQL Server中的计算机名
    WinCC的画面使用技巧
    用VB脚本复制文件夹并跳过重复文件
    如何在WinCC的VB脚本内实现延时功能
    用vbs和ADSI管理Windows账户
    oracle ROW_NUMBER() OVER(PARTITION BY '分组' ORDER BY '排序' DESC) 用法
  • 原文地址:https://www.cnblogs.com/jecyhw/p/3914697.html
Copyright © 2011-2022 走看看