算法模板: 二分法 (Binary Search)

[lewenweijia]

// Binary Search
// you can assumpt arr is sorted
function binarySearch(arr, target) {
  let l = 0;
  let h = arr.length - 1;

  while (l <= h) {
    let mid = l + ((h - l) / 2);
    if (arr[mid] === target) {
      return mid;
    } else if (arr[mid] < target) {
      l = mid + 1;
    } else {
      h = mid - 1;
    }
  }

  return -1;
 }

[lewenweijia]

常见题目类型:

1. 具体值
2. 符合条件C(x)的最值