提取不重复的整数

#include<iostream>
#include<string>
using namespace std;
void main(){
int n,i=0;
cin >> n;
char a[100],b[100];
while (n != 0){  //将整数转换成字符
a[i++] = n % 10 + '0';
n = n / 10;
}
a[i] = '\0';
cout << a << endl;

int j = 0,m=0;
while (a[j] == '0'){  //去除开头的0；
j++;
}
b[m++] = a[j];
j++;
int len = strlen(a);
for (int i = j; i < len; i++){ //将a中去重赋值给b
int flag = 1;
for (int k = 0; k < m; k++){
if (a[i] == b[k])
flag = 0;
}
if (flag){
b[m++] = a[i];
}
}

b[m] = '\0';
cout << b << endl;
system("pause");
}