2283. Check if Number Has Equal Digit Count and Digit Value

problem

solution

class Solution {
public:
    bool digitCount(string num) {
        vector<int> his(10,0);
        for(char c:num) his[c-'0']++;
        for(int i=0;i<num.size();++i){
            if(his[i] != num[i]-'0') return false;
        }
        return true;
    }
};

analysis

• time complexity O(n)
• space complexity O(1)