View Compilation Error

0_0_2191081_19881.cpp: In function `void dfs(int, int, int)':
0_0_2191081_19881.cpp:50: error: `r' undeclared (first use this function)
0_0_2191081_19881.cpp:50: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_2191081_19881.cpp:50: error: `c' undeclared (first use this function)
0_0_2191081_19881.cpp:53: error: `now' undeclared (first use this function)
0_0_2191081_19881.cpp: In function `void solve()':
0_0_2191081_19881.cpp:61: error: `tx' undeclared (first use this function)
0_0_2191081_19881.cpp:61: error: `ty' undeclared (first use this function)