Problems › TypeScript › patterns
How deep does this nest
A config linter reports the deepest level of nested parentheses in an expression, because past a certain depth nobody can read it.
- Depth counts open parentheses that have not been closed yet.
- Text with no parentheses has a depth of zero.
- The input is well formed: every opener has its closer.
- Characters other than parentheses are ignored.
deepestNesting(expression: string) → int
Where you start
function deepestNesting(expression: string): number {
}Worked examples
| Call | Result |
|---|---|
deepestNesting("(1+(2*3)+((8)/4))+1") | 3 |
deepestNesting("(1)+((2))+(((3)))") | 3 |
deepestNesting("1+2") | 0 |
deepestNesting("") | 0 |
Hint
You do not need to store anything — a counter that rises on an opener and falls on a closer is a stack whose only interesting property is its height.
Reference solution in TypeScript
function deepestNesting(expression: string): number {
let depth = 0;
let deepest = 0;
for (const ch of expression) {
if (ch === "(") {
depth += 1;
if (depth > deepest) deepest = depth;
} else if (ch === ")") {
depth -= 1;
}
}
return deepest;
}