LeetCode-1189. Maximum number of balloons

Give you a string text, You need to use text To piece together as many words as possible "balloon"（ balloon ）.

character string text Each letter in can only be used once at most . Please return the maximum number of words you can piece together "balloon".

Example 1：

Input ：text = "nlaebolko"
Output ：1
Example 2：

Input ：text = "loonbalxballpoon"
Output ：2
Example 3：

Input ：text = "leetcode"
Output ：0
 

Tips ：

1 <= text.length <= 10^4
text  All consist of lowercase English letters

#include<iostream>
#include<unordered_map>
#include<unordered_set>
using namespace std;

class Solution {
public:
    int maxNumberOfBalloons(string text) {
        int minval = INT_MAX;
        std::string str = "balloon";
        unordered_set<char> filter;            /*  Record whether to access all  */
        unordered_map<char, int>::iterator it;
        unordered_map<char, int> cur;
        unordered_map<char, int> mp;
        mp['b'] = 1;
        mp['a'] = 1;
        mp['l'] = 2;
        mp['o'] = 2;
        mp['n'] = 1;
        for (char c : text) {
            if (cur.count(c) == 0) {
                cur[c] = 1;
            }
            else {
                cur[c]++;
            }
        }

        it = cur.begin();
        while (it != cur.end()) {
            if (mp.count(it->first) != 0) {
                filter.insert(it->first);
                if ((cur[it->first] / mp[it->first]) < minval) {
                    minval = cur[it->first] / mp[it->first];
                }
            }
            it++;
        }
        if (filter.size() != 5) {
            minval = 0;
        }

        return minval;
    }
};