Interview 150

Binary Search

Problem
LC 704
File
interview150_LC704BinarySearch.java
Path
pkg5leetcode/interview150/interview150_LC704BinarySearch.java
Package
pkg5leetcode.interview150
Command
java pkg5leetcode/interview150/interview150_LC704BinarySearch.java
Approach
Classic binary search on sorted array.
Complexity
Time O(log n), Space O(1)

LeetCode solutions

There is no in-browser runner. This is the file from the curriculum, unchanged.

pkg5leetcode/interview150/interview150_LC704BinarySearch.java
1package pkg5leetcode.interview150;2 3/*4 * Binary Search | LC 7045 * APPROACH: Classic binary search on sorted array.6 * COMPLEXITY: Time O(log n), Space O(1)7 */8public class interview150_LC704BinarySearch {9    static int search(int[] nums, int target) {10        int lo = 0, hi = nums.length - 1;11        while (lo <= hi) {12            int mid = lo + (hi - lo) / 2;13            if (nums[mid] == target) return mid;14            if (nums[mid] < target) lo = mid + 1;15            else hi = mid - 1;16        }17        return -1;18    }19 20    public static void main(String[] args) {21        check(search(new int[]{-1, 0, 3, 5, 9, 12}, 9) == 4, "case1");22        check(search(new int[]{-1, 0, 3, 5, 9, 12}, 2) == -1, "case2");23        System.out.println("all tests passed");24    }25 26    static void check(boolean cond, String name) {27        if (!cond) throw new AssertionError("FAILED: " + name);28        System.out.println("  PASS " + name);29    }30}