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 104), 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题意：有n个点，m条边，相邻的点不能相同的颜色，然后有k种涂颜色的方法，如果符合条件的话，就输出这种方案总共涂了几个颜色，如果不符合就输出No
解题思路：先结构体存储边即v,w，然后在判断每一种符不符合的时候，输入的每一种颜色都放到set里面，然后hash判断a[v[i].v]==a[v[i].w]，如果相等就说明不符合直接退出循环输出No，不等的话就输出set的size
#include<iostream>
#include<cstdio>
#include<vector>
#include<set>
using namespace std;
const int maxn=1e4+1;
struct vertex{
int v,w;
};
int main(void)
{
int n,m;
scanf("%d %d",&n,&m);
vector<vertex>vq(m);
for(int i=0;i<m;i++)
scanf("%d %d",&vq[i].v,&vq[i].w);
int k;
scanf("%d",&k);
while(k--)
{
int a[maxn]={0};
set<int>ans;
for(int i=0;i<n;i++)
{
scanf("%d",&a[i]);
ans.insert(a[i]);
}
bool flag=true;
for(int i=0;i<m;i++)
{
if(a[vq[i].v]==a[vq[i].w])
{
flag=false;
break;
}
}
if(flag) printf("%d-coloring\n",ans.size());
else printf("No\n");
}
return 0;
}