Given an array of n elements repeats, remove the repeating data and return the new array. Some tests cases below:
console.log( deleteDuplicate([1,2,3,4,4,5,4,3,2,1,67,4,3]) )
> [ 1, 2, 3, 4, 5, 67 ]
console.log(deleteDuplicate( ["Juan","Pedro","Juan"] ));
> [ 'Juan', 'Pedro' ]Search a sorted array by repeatedly dividing the search interval in half. Begin with an interval covering the whole array. If the value of the search key is less than the item in the middle of the interval, narrow the interval to the lower half. Otherwise narrow it to the upper half. Repeatedly check until the value is found or the interval is empty.
The idea of binary search is to use the information that the array is sorted and reduce the time complexity to O(Log n).
We basically ignore half of the elements just after one comparison:
- Compare x with the middle element.
- If x matches with middle element, we return the mid index.
- Else If x is greater than the mid element, then x can only lie in right half subarray after the mid element. So we recur for right half.
- Else (x is smaller) recur for the left half.
Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M.
| Symbol | Value |
|---|---|
| V | 5 |
| I | 1 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1000 |
For example, 2 is written as II in Roman numeral, just two one's added together. 12 is written as XII, which is simply X + II. The number 27 is written as XXVII, which is XX + V + II.
Roman numerals are usually written largest to smallest from left to right. However, the numeral for four is not IIII. Instead, the number four is written as IV. Because the one is before the five we subtract it making four. The same principle applies to the number nine, which is written as IX. There are six instances where subtraction is used:
I can be placed before V (5) and X (10) to make 4 and 9. X can be placed before L (50) and C (100) to make 40 and 90. C can be placed before D (500) and M (1000) to make 400 and 900. Given an integer, convert it to a roman numeral.
Example 1:
Input: num = 3 Output: "III" Example 2:
Input: num = 4 Output: "IV" Example 3:
Input: num = 9 Output: "IX" Example 4:
Input: num = 58 Output: "LVIII" Explanation: L = 50, V = 5, III = 3. Example 5:
Input: num = 1994 Output: "MCMXCIV" Explanation: M = 1000, CM = 900, XC = 90 and IV = 4.
Constraints:
1 <= num <= 3999 Accepted 463,840 Submissions 814,452