create a function to do binary search
const bsearch = (nums: number[], target: number): number => { let l = 0; let r = nums.length - 1; while (l <= r) { const mid = Math.floor((l + r) / 2); if (nums[mid] === target) { return mid; } if (nums[mid] < target) { l = mid + 1; } if (nums[mid] > target) { r = mid - 1; } } return -1; }; console.log(bsearch([1, 2, 3, 4, 5], 3)); console.log(bsearch([1, 2, 3, 4, 5], 6));