View Compilation Error

0_0_38076133_11266.cpp: In function 'void dfs(int, int)':
0_0_38076133_11266.cpp:31:10: error: expected unqualified-id before '[' token
     auto [x, y, z] = v[u];
          ^
0_0_38076133_11266.cpp:32:13: error: 'x' was not declared in this scope
     if (cnt[x] && cnt[y] && cnt[z])
             ^
0_0_38076133_11266.cpp:32:23: error: 'y' was not declared in this scope
     if (cnt[x] && cnt[y] && cnt[z])
                       ^
0_0_38076133_11266.cpp:32:33: error: 'z' was not declared in this scope
     if (cnt[x] && cnt[y] && cnt[z])
                                 ^
0_0_38076133_11266.cpp: In function 'int main()':
0_0_38076133_11266.cpp:52:34: error: converting to 'std::vector<std::tuple<int, int, int> >::value_type {aka std::tuple<int, int, int>}' from initializer list would use explicit constructor 'constexpr std::tuple< <template-parameter-1-1> >::tuple(_UElements&& ...) [with _UElements = {int&, int&, int}; <template-parameter-2-2> = void; _Elements = {int, int, int}]'
         v.push_back({i, j, i + j});
                                  ^