Group Programming Ladder Race l2-023 graph coloring problem

l2-023. Graph coloring problem time limit (ms)
Memory Limit 65536 KB
Code length limit 8000 B
Chen, standard author of the procedure for the award of questions

The graph coloring problem is a well-known NP-complete problem. Given the graph G = (V, E), ask if you can assign a color to each vertex in V with a k color, so that no two adjacent vertices have the same color.

But the question is not to solve this coloring problem, but for a given color assignment, please decide if this is a solution to the graph coloring problem.

Input Format:

The input gives 3 integer V (0 < v <= 500), E (>= 0) and K (0 < K <= V) in the first row, respectively, the number of vertices, sides, and colors of the graph. Vertices and colors are numbered from 1 to v. Then the E line, each row gives the number of the two endpoints of an edge. After the information in the graph is given, a positive integer n (<= 20) is given, which is the number of color assignment schemes to be checked. Then n rows, each row is given the color of the V vertex (the number I represents the color of the vertex i), and the numbers are separated by a space. The topic guarantees that the given graph is valid (i.e., there is no self-loop and heavy-side).

output Format:

For each color allocation scheme, if it is a solution to the graph coloring problem, the output is "Yes", otherwise the output "No", each sentence occupies a row. Input Sample:

6 8 3
2 1
1 3
4 6 2
5
2 4
5 4
5 6
3 6
4
1 2 3 3 1 2
4 5 6 6 4 5
1 2 3 4 5 6
2 3 4 2 3 4

Sample output:

Yes
Yes
no
no

Note: The color must be of type K

#include <iostream> #include <cstdio> #include <cstring> #include <string> #include < algorithm> #include <cmath> #include <map> #include <set> #include <stack> #include <queue

> #include <vector> #include <bitset> using namespace std;

#define LL Long Long const int INF = 0X3F3F3F3F;
int n, m, K;
int u[250090], v[250090];

int visit[505],a[505]; int main () {while (~scanf ("%d%d%d", &n, &m, &k)) {for (int i = 1; I <= m; i++) scanf ("%d%d", &u[i
		], &v[i]);
		int q;
		scanf ("%d", &q);
			while (q--) {memset (visit, 0, sizeof visit);
			int cnt = 0, flag = 1;
				for (int i = 1; I <= n; i++) {scanf ("%d", &a[i]);
				if (Visit[a[i]]) continue;
			Visit[a[i]] = 1, cnt++;
			} if (cnt! = k) {printf ("no\n"); continue;}
			for (int i = 1; I <= m; i++) if (a[u[i] [= a[v[i]]) flag = 0;
			if (flag) printf ("yes\n");
		else printf ("no\n");
}} return 0; }