-
Notifications
You must be signed in to change notification settings - Fork 8
/
sort-colors.js
43 lines (41 loc) · 1.23 KB
/
sort-colors.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
// Given an array with n objects colored red, white or blue, sort them in-place so that objects of the same color are adjacent, with the colors in the order red, white and blue.
//
// Here, we will use the integers 0, 1, and 2 to represent the color red, white, and blue respectively.
//
// Note: You are not suppose to use the library's sort function for this problem.
//
// Example:
//
//
// Input: [2,0,2,1,1,0]
// Output: [0,0,1,1,2,2]
//
// Follow up:
//
//
// A rather straight forward solution is a two-pass algorithm using counting sort.
// First, iterate the array counting number of 0's, 1's, and 2's, then overwrite array with total number of 0's, then 1's and followed by 2's.
// Could you come up with a one-pass algorithm using only constant space?
//
//
/**
* @param {number[]} nums
* @return {void} Do not return anything, modify nums in-place instead.
*/
var sortColors = function(nums) {
var colors = [0, 0, 0],
len = nums.length;
nums.forEach(function(v) {
colors[v]++;
});
var i = 0, j = 0;
for (;i < len; ++i) {
var c = 0;
while (colors[j] <= 0) {
++j;
}
c = j;
--colors[j];
nums[i] = c;
}
};