1154 Vertex Coloring (25分)
A proper vertex coloring is a labeling of the graph’s vertices with colors such that no two vertices sharing the same edge have the same color. A coloring using at most k colors is called a (proper) k-coloring.
Now you are supposed to tell if a given coloring is a proper k-coloring.
Input Specification:
Each input file contains one test case. For each case, the first line gives two positive integers N and M (both no more than 10
4
), being the total numbers of vertices and edges, respectively. Then M lines follow, each describes an edge by giving the indices (from 0 to N−1) of the two ends of the edge.
After the graph, a positive integer K (≤ 100) is given, which is the number of colorings you are supposed to check. Then K lines follow, each contains N colors which are represented by non-negative integers in the range of int. The i-th color is the color of the i-th vertex.
Output Specification:
For each coloring, print in a line k-coloring if it is a proper k-coloring for some positive k, or No if not.
Sample Input:
10 11
8 7
6 8
4 5
8 4
8 1
1 2
1 4
9 8
9 1
1 0
2 4
4
0 1 0 1 4 1 0 1 3 0
0 1 0 1 4 1 0 1 0 0
8 1 0 1 4 1 0 5 3 0
1 2 3 4 5 6 7 8 8 9
Sample Output:
4-coloring
No
6-coloring
No
就是N個頂點，編號從0到N-1，然後給出M條邊，用兩端頂點表示。 如果沒有共享同一條邊的兩個頂點顏色一樣的 頂點圖就稱之爲 k-coloring.
set判斷K是多少，每個頂點圖 過一遍所有的邊就搞定了
#include <iostream>
#include <algorithm>
using namespace std;
#include <vector>
#include <unordered_set>
int main()
{
int N,M;
cin>>N>>M;
int vertex[N];
int edge[M][2];
for(int i=0; i<M; i++)
{
cin>>edge[i][0]>>edge[i][1];
}
int num;
cin>>num;
for(int i=0; i<num; i++)
{
unordered_set<int> sett;
for(int q=0; q<N; q++)
{
cin>>vertex[q];
sett.insert(vertex[q]);
}
//對頂點進行判斷
int sign=1;
for(int i=0; i<M; i++)
{
int a=edge[i][0];
int b=edge[i][1];
if(vertex[edge[i][0]]==vertex[edge[i][1]]){
sign=0;
break;
}
}
if(sign==0){
cout<<"No"<<endl;
}
else{
cout<<sett.size()<<"-coloring"<<endl;
}
}
return 0;
}