Build a tiny version of the Unix uniq command. Given a list of lines, drop adjacent duplicate lines (keep only the first occurrence in each consecutive run) and return the surviving lines joined by newline characters (\n).
Function signature:
uniq(lines)
Example:
Input: lines = ["a", "a", "b", "c", "c", "c", "a"] Output: "a\nb\nc\na" When printed: a b c a
Notice that the trailing "a" survives because it is not adjacent to the first run of "a"s — only consecutive duplicates are removed.
Walk the input array and push a line into your result only if it differs from the line you most recently pushed. Compare against the LAST element of
result, not against all previous elements.
if (result.length === 0 || lines[i] !== result[result.length - 1]) {
result.push(lines[i]);
}
The full solution:
class Solution {
uniq(lines) {
let result = [];
for (let i = 0; i < lines.length; i++) {
if (result.length === 0 || lines[i] !== result[result.length - 1]) {
result.push(lines[i]);
}
}
return result.join("\n");
}
}
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