View Compilation Error

0_0_11657413_18827.cpp:52: error: uninitialized const `use'
0_0_11657413_18827.cpp:101: error: `maxn' was not declared in this scope
0_0_11657413_18827.cpp: In function `int main()':
0_0_11657413_18827.cpp:106: error: `a' undeclared (first use this function)
0_0_11657413_18827.cpp:106: error: (Each undeclared identifier is reported only once for each function it appears in.)