View Compilation Error

0_0_11303733_20132.cpp: In function `void dfs(int)':
0_0_11303733_20132.cpp:26: error: `tr' undeclared (first use this function)
0_0_11303733_20132.cpp:26: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_11303733_20132.cpp:26: error: expected `;' at end of input
0_0_11303733_20132.cpp:26: error: expected `}' at end of input