POJ-1575(一直WA，但找不到原因)

#include<iostream>
#include<string>
using namespace std;

bool isVowel(char c){
if(c=='a'||
c=='e'||
c=='i'||
c=='o'||
c=='u'){
return true;
}else{
return false;
}
}

bool rule(string s){
bool containVowelFlag=false;
int cntVowel=0;
int cntConsonant=0;
char lastC='1';

for(int i=0;i<s.length();i++){
if(isVowel(s[i])){
cntConsonant=0;
cntVowel++;
if(cntVowel==3){
return false;
}
containVowelFlag=true;
}else{
cntVowel=0;
cntConsonant++;
if(cntConsonant==3){
return false;
}
}

if(s[i]==lastC){
if(lastC!='e'&&
lastC!='o'){
return false;
}
}

lastC=s[i];
}

if(!containVowelFlag){
return false;
}

return true;
}

int main(int argc, char *argv[]){
string s;
while(cin>>s,s!="end"){
if(rule(s)){
cout<<"<"<<s<<"> is acceptable."<<endl;
}else{
cout<<"<"<<s<<"> is not acceptable"<<endl;
}
}
return 0;
}