Zstuoj 4191 Non-circular graph finding ring (DFS)

Chinese questions

Direct Dfs down, encounter the point of repeated visits, determine the ring three-part XOR and is greater than 0

Code:

#include <cstdio> #include <cstring> #include <algorithm>using namespace std;const int N = 100005;const    int M = 400005;int N, m;struct Edge {int u, V, W;        Edge () {} edge (int u, int v, int w) {this->u = u;        This->v = v;    This->w = W;    }} edge[m];int Head[n], nxt[m], en;void init () {memset (head,-1, sizeof (head)); En = 0;}    void Add_edge (int u, int v, int w) {Edge[en] = Edge (U, V, W);    Nxt[en] = Head[u]; Head[u] = en++;}    int vis[n], xor[n];bool dfs (int u, int x) {Vis[u] = 1;    Xor[u] = x;        for (int i = head[u]; i + 1; i = Nxt[i]) {int v = EDGE[I].V;        int w = EDGE[I].W;            if (Vis[v]) {if ((xor[u]^xor[v]^w) > 0) return true;        Continue    } if (Dfs (v, x^w)) return true; } return false;}    BOOL Judge () {for (int i = 1; I <= n; i++) if (!vis[i]) if (DFS (i, 0)) return true; return false;} int main () {while (~scanf ("%d%d", &n, &m)) {       Init ();        int U, V, W;            while (m--) {scanf ("%d%d%d", &u, &v, &w);            Add_edge (U, V, W);        Add_edge (V, U, W);        } memset (Vis, 0, sizeof (VIS)); printf ("%s\n", Judge ()?    "Yes": "No"); } return 0;}

Zstuoj 4191 Non-circular graph finding ring (DFS)