func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 1e6 + 10, INF = 0x3f3f3f3f, MOD = 1e9 + 7;   int n;   char s[N][10];   int val[N];   int l[N], r[N];   set<int> st[N];   void go(int u, int v) {     if (st[v].size() > st[u].size()) {       st[u].swap(st[v]);     }     for (int x : st[v]) st[u].insert(x);     set<int>().swap(st[v]);   }   void dfs(int u) {     if (*s[u] ==  I ) {       st[u].insert(u);       return;     }     if (*s[u] ==  N ) {       int v = l[u];       dfs(v);       val[u] = !val[v];       go(u, v);     } else if (*s[u] ==  A ) {       int v1 = l[u], v2 = r[u];       dfs(v1);       dfs(v2);       val[u] = val[v1] & val[v2];       if (val[u] != ((val[v1] ^ 1) & val[v2])) {         go(u, v1);       }       if (val[u] != (val[v1] & (val[v2] ^ 1))) {         go(u, v2);       }     } else if (*s[u] ==  O ) {       int v1 = l[u], v2 = r[u];       dfs(v1);       dfs(v2);       val[u] = val[v1] | val[v2];       if (val[u] != ((val[v1] ^ 1) | val[v2])) {         go(u, v1);       }       if (val[u] != (val[v1] | (val[v2] ^ 1))) {         go(u, v2);       }     } else {       int v1 = l[u], v2 = r[u];       dfs(v1);       dfs(v2);       val[u] = val[v1] ^ val[v2];       if (val[u] != ((val[v1] ^ 1) ^ val[v2])) {         go(u, v1);       }       if (val[u] != (val[v1] ^ (val[v2] ^ 1))) {         go(u, v2);       }     }   }   int main() {     ios::sync_with_stdio(0);     cin.tie(0);     scanf( %d , &n);     for (int i = 1; i <= n; ++i) {       scanf( %s , s[i]);       if (*s[i] ==  I ) {         scanf( %d , val + i);       } else if (*s[i] ==  N ) {         scanf( %d , l + i);       } else {         scanf( %d%d , l + i, r + i);       }     }     dfs(1);     for (int i = 1; i <= n; ++i) {       if (*s[i] ==  I ) {         printf( %d , val[1] ^ (st[1].count(i)));       }     }     puts(  );     return 0;   }   