View Compilation Error

0_0_17512586_19746.cpp: In function 'bool jud(int)':
0_0_17512586_19746.cpp:13:14: error: 'inf' was not declared in this scope
     ma1=ma2=-inf;
              ^
0_0_17512586_19746.cpp:17:12: error: 'b' was not declared in this scope
         if(b[i]-a[i]>mid)
            ^
0_0_17512586_19746.cpp:17:17: error: 'a' was not declared in this scope
         if(b[i]-a[i]>mid)
                 ^
0_0_17512586_19746.cpp: In function 'int main()':
0_0_17512586_19746.cpp:51:22: error: 'ok' was not declared in this scope
             if(ok(mid))  
                      ^