// Binary Search Implementation
function binarySearch(arr, target) {
    let left = 0;
    let right = arr.length - 1;
    
    while (left <= right) {
        const mid = Math.floor((left + right) / 2);
        
        if (arr[mid] === target) {
            return mid; // Found the target
        } else if (arr[mid] < target) {
            left = mid + 1; // Search right half
        } else {
            right = mid - 1; // Search left half
        }
    }
    
    return -1; // Target not found
}

// Example usage
const numbers = [1, 3, 5, 7, 9, 11, 13];
console.log(binarySearch(numbers, 9)); // Output: 4