704.二分查找

// [left,right] 左闭右闭区间
const search = (nums, target) => {
    let left = 0
    let right = nums.length - 1
    while (left <= right) {
        const mid = left + Math.floor((right - left) / 2)
        if (nums[mid] > target) {
            right = mid - 1 // 去左面闭区间寻找
        } else if (nums[mid] < target) {
            left = mid + 1 // 去右面闭区间寻找
        } else {
            return mid
        }
    }
    return -1
}

// [left,right) 左闭右开区间
const search = (nums, target) => {
    let left = 0, right = nums.length;
    while (left < right) {
        let mid = left + Math.floor((right - left)/2);
        if (nums[mid] > target) {
            right = mid; // 去左区间寻找
        } else if (nums[mid] < target) {
            left = mid + 1; // 去右区间寻找
        } else {
            return mid;
        }
    }
    return -1;
};