【leetcode】1189. Maximum number of "balloons"

subject ：
1189. “ balloon ” Maximum number of
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

class Solution {
    
    public int maxNumberOfBalloons(String text) {
    
        char[] ch = text.toCharArray(); 
        Map<Character,Integer> map = new HashMap<>();
        for(int i = 0; i < ch.length;i++){
    
            map.put(ch[i],map.getOrDefault(ch[i],0) + 1 );
        }
        int res = 0;
        int b = map.getOrDefault('b',0);
        int a = map.getOrDefault('a',0);
        int l = map.getOrDefault('l',0) / 2;
        int o = map.getOrDefault('o',0) / 2;
        int n = map.getOrDefault('n',0);
        res = Math.min(a,b);
        res = Math.min(res,l);
        res = Math.min(res,o);
        res = Math.min(res,n);
        return res;
    }  
}