[Data structure] Binary search code template

Source: Qin Chao

Python

left, right = 0, len(array) - 1 
while left <= right: 
	  mid = (left + right) / 2 
	  if array[mid] == target: 
		    # find the target!! 
		    break or return result 
	  elif array[mid] < target: 
		    left = mid + 1 
	  else: 
		    right = mid - 1

C/C++

int binarySearch(const vector<int>& nums, int target) {
    
    
	int left = 0, right = (int)nums.size()-1;
	
	while (left <= right) {
    
    
		int mid = left + (right - left)/ 2;
		if (nums[mid] == target) return mid;
		else if (nums[mid] < target) left = mid + 1;
		else right = mid - 1;
	}
	
	return -1;
}

Java

public int binarySearch(int[] array, int target) {
    
    
    int left = 0, right = array.length - 1, mid;
    while (left <= right) {
    
    
        mid = (right - left) / 2 + left;

        if (array[mid] == target) {
    
    
            return mid;
        } else if (array[mid] > target) {
    
    
            right = mid - 1;
        } else {
    
    
            left = mid + 1;
        }
    }

    return -1;
}

JavaScript

let left = 0, right = len(array) - 1
while (left <= right) {
    
    
  let mid = (left + right) >> 1
  if (array[mid] === target) {
    
     /*find the target*/; return }
  else if (array[mid] < target) left = mid + 1
  else right = mid - 1
}