Check a palindrome
Return whether an ASCII string reads identically forwards and backwards; comparison is case-sensitive. Inputs are valid JSON and must not be modified unless the algorithm uses a local copy. This exercise probes typed data modeling, boundary handling, and algorithm selection.
Input
One JSON value: string. See the sample for its exact shape.
Output
One compact JSON value of type boolean. Strings include JSON quotes; arrays preserve the specified order.
Constraints
Array/string lengths are 0 to 10000 unless stated otherwise. Numbers are integers in [-1000000,1000000]; all computed results fit the safe integer range.
Example
Input
"racecar"
Output
true
Example 2 input
"ab ba"
Output
true
Checks a boundary or contrasting case beyond the public examples.
Public test cases (2)
Input
"racecar"
Expected output
true
Input
"hello"
Expected output
false
Hints (2)
- Start with the required output order and the empty-input behavior.
- Compare matching characters from both ends
Target complexity: time O(n) · space O(1)