35.1、题目描述
给定一个排序数组和一个目标值,在数组中找到目标值,并返回其索引。
如果目标值不存在于数组中,返回它将会被按顺序插入的位置。你可以假设数组中无重复元素。
35.2、示例
示例 1:
输入: [1,3,5,6], 5
输出: 2
示例 2:
输入: [1,3,5,6], 2
输出: 1
示例 3:
输入: [1,3,5,6], 7
输出: 4
示例 4:
输入: [1,3,5,6], 0
输出: 0
35.3、循环遍历
var searchInsert = function (nums, target) {
for (var i = 0; i < nums.length; i++) {
if (target <= nums[i]) {
return i
}
}
return nums.length;
};
console.log(searchInsert([1, 3, 5, 6], 5));
console.log(searchInsert([1, 3, 5, 6], 2));
console.log(searchInsert([1, 3, 5, 6], 7));
35.4、二分法
var searchInsert = function (nums, target) {
let left = 0, right = nums.length - 1;
while (left <= right) {
var mid = Math.floor((left + right) / 2)
if (target < nums[mid]) {
right = mid - 1;
} else if (target == nums[mid]) {
return mid
}
else {
left = mid + 1;
}
}
return right == nums.length ? right : right + 1;
};
console.log(searchInsert([1, 3, 5, 6], 5));
console.log(searchInsert([1, 3, 5, 6], 2));
console.log(searchInsert([1, 3, 5, 6], 7));