View Compilation Error

0_0_2530067_27003.cpp: In function `void BigNumAdd(char*, char*)':
0_0_2530067_27003.cpp:9: error: `strrev' undeclared (first use this function)
0_0_2530067_27003.cpp:9: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_2530067_27003.cpp:12: error: invalid operands of types `char*' and `char*' to binary `operator+'
0_0_2530067_27003.cpp:13: error: incompatible types in assignment of `int' to `int[200]'
0_0_2530067_27003.cpp:17: error: invalid conversion from `char*' to `int'
0_0_2530067_27003.cpp:18: error: incompatible types in assignment of `int' to `int[200]'
0_0_2530067_27003.cpp:23: error: invalid conversion from `char*' to `int'
0_0_2530067_27003.cpp:24: error: incompatible types in assignment of `int' to `int[200]'
0_0_2530067_27003.cpp:28: error: incompatible types in assignment of `int' to `int[200]'