View Compilation Error

828097_0_0_29831.cpp: In function `void dfs(int)':
828097_0_0_29831.cpp:13: error: `i' undeclared (first use this function)
828097_0_0_29831.cpp:13: error: (Each undeclared identifier is reported only once for each function it appears in.)
828097_0_0_29831.cpp:13: error: `p' undeclared (first use this function)