View Compilation Error

0_0_33824656_3983.cpp: In function 'void merge(int, int)':
0_0_33824656_3983.cpp:30:3: error: 'else' without a previous 'if'
   else ok=0;    
   ^
0_0_33824656_3983.cpp: In function 'int main()':
0_0_33824656_3983.cpp:45:26: error: 'i' was not declared in this scope
            if(a==b ||  z[i]!=i ) ok=0;
                          ^
0_0_33824656_3983.cpp:52:27: error: 'i' was not declared in this scope
             if(a==b ||  z[i]!=i ) ok=0;
                           ^