第一个只出现一次的字符

#include <iostream>#include <string>using namespace std;char OutOnceTimes(string str);int main(){string str;cin>>str;char OnceTime=OutOnceTimes(str);system("pause");return 0;}char OutOnceTimes(string str){unsigned int hashTable[256];int j=0;while(j!=256){hashTable[j]=0;++j;}int i=0;while (str[i]!='\0'){hashTable[str[i]]++;i++;}int k=0;while (str[k]!='\0'){if (hashTable[str[k]]==1){return hashTable[str[k]];}k++;}return 0;}</string></iostream>