Given an object obj
, return an inverted object invertedObj
.
The invertedObj
should have the keys of obj
as values and the values of obj
as keys. It is guaranteed that the values in obj
are only strings. The function should handle duplicates, meaning that if there are multiple keys in obj
with the same value, the invertedObj
should map the value to an array containing all corresponding keys.
Example 1:
Input: obj = {"a": "1", "b": "2", "c": "3", "d": "4"} Output: invertedObj = {"1": "a", "2": "b", "3": "c", "4": "d"} Explanation: The keys from obj become the values in invertedObj, and the values from obj become the keys in invertedObj.
Example 2:
Input: obj = {"a": "1", "b": "2", "c": "2", "d": "4"} Output: invertedObj = {"1": "a", "2": ["b", "c"], "4": "d"} Explanation: There are two keys in obj with the same value, the invertedObj mapped the value to an array containing all corresponding keys.
Example 3:
Input: obj = ["1", "2", "3", "4"] Output: invertedObj = {"1": "0", "2": "1", "3": "2", "4": "3"} Explanation: Arrays are also objects therefore array has changed to an object and the keys (indices) from obj become the values in invertedObj, and the values from obj become the keys in invertedObj.
Constraints:
obj
is a valid JSON objecttypeof obj[key] === "string"
2 <= JSON.stringify(obj).length <= 105
function invertObject(obj: Record<any, any>): Record<any, any> {
const ans: Record<any, any> = {};
for (const key in obj) {
if (ans.hasOwnProperty(obj[key])) {
if (Array.isArray(ans[obj[key]])) {
ans[obj[key]].push(key);
} else {
ans[obj[key]] = [ans[obj[key]], key];
}
} else {
ans[obj[key]] = key;
}
}
return ans;
}