Create a map `m` to count the frequency of each implicit character `c` of the string `s`.
* Note: The character `c` is explicit in Rust and C++

---

*Kotlin*
```javascript
var m = s.groupingBy{ it }.eachCount()
```

*Java*
```java
Map<String, Long> m = Stream.of(s.split("")).collect(Collectors.groupingBy(it -> it, Collectors.counting()));
```

*Javascript*
```javascript
let m = new Map(Object.entries(_.countBy(s.split(''))));
```

*Python3*
```python
m = Counter(s)
```

*Rust*
```rust
let m = s.chars().fold(HashMap::new(), |mut m, c| { *m.entry(c).or_insert(0) += 1; m });
```

*C++*
```cpp
using Map = unordered_map<char, int>;
Map m;
for (auto c: s) ++m[c];
```