HDU 4337 King arthur& #39; s Knights it outputs a Hamiltonian circuit

N Points m article no forward side

It outputs a Hamiltonian circuit

#include <cstdio> #include <cstring> #include <iostream>using namespace std;const int N = 155;int N, m;bo Ol Mp[n][n];int S, T, top, Stack[n];bool vis[n];void _reverse (int l,int R) {while (l<r) swap (stack[l++],stack[r--]);} void expand () {while (1) {BOOL flag = 0;for (int i=1; I<=n && false = = Flag; i++) if (!vis[i] && Mp[t][i] ) {stack[top++]=i; T=i;flag = vis[i] = 1;} if (!flag) return;}} void Hamiltun (int Start) {memset (Vis, 0, sizeof vis); S = Start;for (t=2; t<=n; t++)//randomly find two adjacent nodes S and TIF (Mp[s][t]) break; top = 0; Stack[top++]=s; Stack[top++]=t;vis[s] = vis[t] = True;while (1) {expand ();//expand on them a path that is as long as possible without repeated nodes: Step 1_reverse (0,top-1); swap (s,t); expand (); On the basis of the extension of a long, no-repeat-node path int mid=0;if (!mp[s][t])//If s is not adjacent to T, can construct a loop so that the new S and T adjacent {//Set the path s→t k+2 nodes, s,v1,v2 ... vk and T. Can prove the existence of node vi,i∈[1,k), satisfies the VI and T adjacent, and Vi+1 and S adjacent for (int i=1; i<top-2; i++) if (Mp[stack[i]][t] && Mp[stack[i+1]][s] ) {mid=i+1; break;} Turn the original path into S→vi→t→vi+1→s, that is to form a loop _reverse (mid,top-1); T=stack[tOP-1];} if (top==n) break;//Now we have a loop that does not have a repeating node. Assuming it's length is N, then the Hamilton Loop is found//otherwise, because the entire graph is connected, so in this way, there must be a point adjacent to the loop outside the circuit//then from the point where the circuit is disconnected, Change back to a path, and then follow the method of step 1 as far as possible to extend the path for (int i = 1, j; I <= N; i++) if (!vis[i]) {for (j=1; j<top-1; j + +) if (Mp[stack[j]][i]) Brea K;if (Mp[stack[j]][i]) {t=i; mid=j;break;}} S=stack[mid-1];_reverse (0,mid-1); _reverse (mid,top-1); Stack[top++]=t;vis[t]=true;}} int main () {while (cin>>n>>m) {memset (MP, 0, sizeof MP), for (int i = 1, u, v; I <= m; i++) {scanf ("%d%d", & Amp;u, &v); Mp[u][v] = mp[v][u] = 1;} Hamiltun (1); for (int i = 0; i < top; i++) printf ("%d%c", Stack[i], i==top-1? ' \ n ': ');} return 0;}

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HDU 4337 King arthur& #39; s Knights it outputs a Hamiltonian circuit