Runtime 1 ms Beats 98.18%
Memory 40.9 MB Beats 82%

#N2283. Check if Number Has Equal Digit Count and Digit Value
problem link
#solution

class Solution {
    public boolean digitCount(String num) {
        Map<Integer, Integer> map = new HashMap<>();
        for(char c: num.toCharArray()){
            int n=c-'0';
            map.put(n, map.getOrDefault(n, 0) +1);
        }

        for(int i=0; i<num.length(); i++){
            if(!map.containsKey(i) && num.charAt(i)!='0' 
            || map.containsKey(i) && map.get(i)!=num.charAt(i)-'0') return false;
        }
        return true;
    }
}