View Compilation Error

0_0_38044575_23214.cpp: In function 'int main()':
0_0_38044575_23214.cpp:18:92: error: expected ']' before ')' token
                 if(a[i<='z'&&a[i]>='a'||a[i<='Z'&&a[i]>='A'||a[i]=='_'||a[i<='9'&&a[i]>='0') 
                                                                                            ^
0_0_38044575_23214.cpp:18:92: error: expected ']' before ')' token
0_0_38044575_23214.cpp:18:92: error: expected ']' before ')' token