View Compilation Error

0_0_9502891_10852.cpp: In function `int spfa(int, int, int)':
0_0_9502891_10852.cpp:50: error: `tai' undeclared (first use this function)
0_0_9502891_10852.cpp:50: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_9502891_10852.cpp: In function `int main()':
0_0_9502891_10852.cpp:84: error: `w' undeclared (first use this function)
0_0_9502891_10852.cpp:115: error: `c' undeclared (first use this function)