func_code_string: #include <bits/stdc++.h>   using namespace std;   const int inf = 0x3f3f3f3f, oo = inf;   inline long long read() {     register long long x = 0;     char f = 0;     register char c = getchar();     for (; !isdigit(c); c = getchar()) f |= (c ==  - );     for (; isdigit(c); c = getchar()) x = (x << 1) + (x << 3) + (c ^ 48);     return f ? -x : x;   }   inline double readdb() {     register double x = 0, p = 0.1;     register char f = 0, c = getchar();     for (; !isdigit(c); c = getchar()) f |= (c ==  - );     for (; isdigit(c); c = getchar()) x = x * 10 + (c ^ 48);     if (c ==  . )       for (c = getchar(); isdigit(c); c = getchar(), p /= 10)         x = x + (c ^ 48) * p;     return f ? -x : x;   }   inline void write(long long x) {     if (x < 0) x = -x, putchar( - );     if (x >= 10) write(x / 10);     putchar(x % 10 +  0 );   }   inline void writeln(long long x) {     write(x);     puts(  );   }   inline void writeln(long long x, char c, long long y) {     write(x);     putchar(c);     writeln(y);   }   inline void writeln(long long x, char c, long long y, char d, long long z) {     write(x);     putchar(c);     write(y);     putchar(d);     writeln(z);   }   const int maxn = 3e5 + 233;   const int maxm = 6e5 + 233;   struct Edge {     int to, nxt, dist;     Edge() {}     Edge(int to, int nxt, int dist) : to(to), nxt(nxt), dist(dist) {}   } edge1[maxm], edge2[maxm];   int first1[maxn], first2[maxn];   int nume1, nume2;   void Addedge1(int a, int b, int c) {     edge1[nume1] = Edge(b, first1[a], c);     first1[a] = nume1++;   }   int s[maxn], dfn[maxn], low[maxn], dfsclk = 0;   bool Ins[maxn];   int bel[maxn];   int val[maxn], dist[maxn];   void Tarjan(int u, int fa) {     dfn[u] = low[u] = ++dfsclk;     Ins[u] = true;     s[++*s] = u;     for (int e = first1[u]; ~e; e = edge1[e].nxt) {       int v = edge1[e].to;       if (v == fa) continue;       if (!dfn[v]) {         Tarjan(v, u);         low[u] = min(low[u], low[v]);       } else if (Ins[v]) {         low[u] = min(low[u], dfn[v]);       }     }     if (dfn[u] == low[u]) {       bel[0]++;       for (;;) {         int v = s[s[0]--];         Ins[v] = false;         bel[v] = *bel;         if (u == v) break;       }     }   }   void Addedge2(int a, int b, int c) {     edge2[nume2] = Edge(b, first2[a], c);     first2[a] = nume2++;   }   void rebuild() {     memset(val, false, sizeof(val));     for (int i = 0; i < nume1; i += 2) {       int u = bel[edge1[i ^ 1].to];       int v = bel[edge1[i].to];       int w = edge1[i].dist;       if (u != v) {         Addedge2(u, v, w);         Addedge2(v, u, w);       } else if (w) {         val[u] = true;       }     }   }   int front, rear, q[maxn];   void BFS(int S, int T) {     memset(dist, -1, sizeof(dist));     front = rear = 0;     q[rear++] = S;     dist[S] = val[S];     while (front < rear) {       int u = q[front++];       for (int e = first2[u]; ~e; e = edge2[e].nxt) {         int v = edge2[e].to;         if (dist[v] == -1) {           dist[v] = dist[u] | edge2[e].dist | val[v];           q[rear++] = v;         }       }     }     if (dist[T]) {       puts( YES );     } else {       puts( NO );     }   }   int n, m;   int main() {     n = read(), m = read();     memset(first1, -1, sizeof(first1));     nume1 = 0;     memset(first2, -1, sizeof(first2));     nume2 = 0;     for (register int i = (1); i <= (m); ++i) {       int a = read(), b = read(), c = read();       Addedge1(a, b, c);       Addedge1(b, a, c);     }     memset(dfn, 0, sizeof(dfn));     *bel = 0;     Tarjan(1, 0);     rebuild();     int s = read(), t = read();     BFS(bel[s], bel[t]);     return 0;   }   