View Compilation Error

0_0_26487604_29701.cpp: In function 'int main()':
0_0_26487604_29701.cpp:20:73: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
             if(str[c]=='a'||str[c]=='e'||str[c]=='i'||str[c]=='o'||str=='u')
                                                                         ^