func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxN = (int)1e5 + 10;   int a[maxN];   int n;   vector<pair<int, int> > ans;   int cop[maxN];   bool solve_stupid(int n) {     for (int i = 1; i <= n; i++) cop[i] = a[i];     vector<pair<int, int> > all;     for (int i = 1; i <= n; i++) {       for (int j = i + 1; j <= n; j++) {         int k = 2 * j - i;         if (k <= n) all.emplace_back(i, j);       }     }     int m = all.size();     random_shuffle(all.begin(), all.end());     vector<pair<int, int> > nall;     for (int i = 0; i < min(m, 22); i++) nall.push_back(all[i]);     all = nall;     m = all.size();     for (int mask = 0; mask < (1 << m); mask++) {       bool ok = true;       for (int i = 1; i <= n; i++) {         a[i] = cop[i];       }       for (int bit = 0; bit < m; bit++) {         if (mask & (1 << bit)) {           int x = all[bit].first;           int y = all[bit].second;           int z = 2 * y - x;           a[x] ^= 1;           a[y] ^= 1;           a[z] ^= 1;         }       }       for (int i = 1; i <= n; i++) {         if (a[i] != 0) {           ok = false;           break;         }       }       if (ok) {         for (int bit = 0; bit < m; bit++) {           if (mask & (1 << bit)) ans.push_back(all[bit]);         }         return true;       }     }     return false;   }   int main() {     ios_base::sync_with_stdio(false);     srand(time(0));     cin >> n;     for (int i = 1; i <= n; i++) {       cin >> a[i];     }     while (n > 13) {       vector<pair<int, int> > possible;       possible.emplace_back(0, 0);       for (int i = n; i >= n - 5; i--) {         for (int j = i - 1; j >= n - 5; j--) {           int k = 2 * j - i;           if (k <= 0) continue;           possible.emplace_back(k, j);         }       }       for (int i = n; i >= n - 5; i--) {         int j = n - 6;         int k = 2 * j - i;         if (k >= 1) {           possible.emplace_back(k, j);         }       }       bool ok = false;       int willi = -1;       int willj = -1;       for (int i = n - 5; i <= n; i++) {         cop[i] = a[i];       }       for (int i = 0; i < possible.size(); i++) {         if (ok) break;         for (int j = i; j < possible.size(); j++) {           for (int q = n - 5; q <= n; q++) a[q] = cop[q];           int x = possible[i].first;           int y = possible[i].second;           int z = 2 * y - x;           if (x >= n - 5) a[x] ^= 1;           if (y >= n - 5) a[y] ^= 1;           if (z >= n - 5) a[z] ^= 1;           int xx = possible[j].first;           int yy = possible[j].second;           int zz = 2 * yy - xx;           if (xx >= n - 5) a[xx] ^= 1;           if (yy >= n - 5) a[yy] ^= 1;           if (zz >= n - 5) a[zz] ^= 1;           if (a[n - 5] == 0 && a[n - 4] == 0 && a[n - 3] == 0 && a[n - 2] == 0 &&               a[n - 1] == 0 && a[n] == 0) {             ok = true;             willi = i;             willj = j;             break;           }         }       }       assert(ok == true);       int x = possible[willi].first;       int y = possible[willi].second;       int z = 2 * y - x;       if (x >= 1) a[x] ^= 1;       if (y >= 1) a[y] ^= 1;       if (z >= 1) a[z] ^= 1;       if (x != 0) ans.push_back(possible[willi]);       int xx = possible[willj].first;       int yy = possible[willj].second;       int zz = 2 * yy - xx;       if (xx >= 1) a[xx] ^= 1;       if (yy >= 1) a[yy] ^= 1;       if (zz >= 1) a[zz] ^= 1;       if (xx != 0) ans.push_back(possible[willj]);       n -= 6;     }     if (solve_stupid(n)) {       cout <<  YES  <<   n ;       cout << ans.size() <<   n ;       for (auto t : ans) {         cout << t.first <<     << t.second <<     << 2 * t.second - t.first              <<   n ;       }     } else {       cout <<  NO  <<   n ;     }     return 0;   }   