1122 Hamiltonian Cycle (25 分)
标签：insert and ++ ase cycle eve enter ali back
The "Hamilton cycle problem" is to find a simple cycle that contains every vertex in a graph. Such a cycle is called a "Hamiltonian cycle".
In this problem, you are supposed to tell if a given cycle is a Hamiltonian cycle.
Each input file contains one test case. For each case, the first line contains 2 positive integers N (2), the number of vertices, and M, the number of edges in an undirected graph. Then M lines follow, each describes an edge in the format Vertex1 Vertex2, where the vertices are numbered from 1 to N. The next line gives a positive integer Kwhich is the number of queries, followed by K lines of queries, each in the format:
n V?1?? V?2?? ... V?n??
where n is the number of vertices in the list, and V?i??‘s are the vertices on a path.
For each query, print in a line YES if the path does form a Hamiltonian cycle, or NO if not.
6 10
6 2
3 4
1 5
2 5
3 1
4 1
1 6
6 3
1 2
4 5
6
7 5 1 4 3 6 2 5
6 5 1 4 3 6 2
9 6 2 1 6 3 4 5 2 6
4 1 2 5 1
7 6 1 3 4 5 2 6
7 6 1 2 5 4 3 1
YES NO NO NO YES NO
就多判断几下了，感觉都不涉及图的知识
1 #include <bits/stdc++.h> 2 using namespace std; 3 int n, m, k, p; 4 vector<int> vt; 5 int v[500][500]; 6 int main(){ 7 cin >> n >> m; 8 int x, y; 9 for(int i = 0; i < m; i++){ 10 cin >> x >> y; 11 v[x][y] = 1; 12 v[y][x] = 1; 13 } 14 cin >> k; 15 while(k--){ 16 cin >> p; 17 vt.clear(); 18 for(int i = 0; i < p; i++){ 19 cin >> x; 20 vt.push_back(x); 21 } 22 set<int> s; 23 if(p == n+1){ 24 if(vt[0] == vt[vt.size()-1]){ 25 bool flag = true; 26 for(int i = 1; i < vt.size(); i++){ 27 if(v[vt[i-1]][vt[i]] == 0){ 28 flag = false; 29 break; 30 } 31 s.insert(vt[i]); 32 } 33 if(flag && s.size() == n){ 34 cout << "YES" << endl; 35 }else{ 36 cout <<"NO"<<endl; 37 } 38 }else{ 39 cout << "NO" << endl; 40 } 41 }else{ 42 cout << "NO" << endl; 43 } 44 } 45 46 return 0; 47 }
标签：insert and ++ ase cycle eve enter ali back
原文地址：https://www.cnblogs.com/zllwxm123/p/11326501.html
