标记数组的做法，哪里有问题

#include <iostream>
#include <cstring>
using namespace std;
#deine maxn 105

char get(char c) {
    switch(c) {
        case '(':
            return ')';
        case ')':
            return '(';
        case '[':
            return ']';
        case ']':
            return '[';
    }
}

int main() {
    string str;
    cin >> str;
    int point[maxn], len = str.length();
    memset(point, 0, sizeof(point));
    for(int i = 1; i < len; i ++) 
        if(str[i - 1] == get(str[i]))
            point[i] = point[i - 1] = 1;
    for(int i = 0; i < len; i ++)
        if(point[i])
            cout << str[i], i ++;
        else
            if(str[i] == '(' || str[i] == '[')
                cout << str[i] << get(str[i]);
            else
                cout << get(str[i]) << str[i];
    return 0;
}