Leetcode c语言-Search Insert Position

Title:

Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order.

You may assume no duplicates in the array.

Here are few examples.
[1,3,5,6], 5 → 2
[1,3,5,6], 2 → 1
[1,3,5,6], 7 → 4
[1,3,5,6], 0 → 0


这道题属于容易题。没什么可分析的,唯一要注意的是如果想减少时间复杂度,肯定不能用暴力遍历。可以采用二分法,或者从两头往中间筛选的方法。不过多分析。


solution:

int searchInsert(int* nums, int numsSize, int target) {
    int i,j;

    if (numsSize==1) {
    	if (target<=nums[0])
    		return 0;
    	else
    		return 1;
    }
    
    i=0;
    j=numsSize-1;
    
    if (target<nums[0])
    	return 0;
    if (target>nums[numsSize-1])
    	return numsSize;

    while (i<=j) {
    	if (target==nums[i])
    		return i;
    	else if (target==nums[j])
    		return j;
    	else if (target<nums[i] && target>nums[i-1])
    		return i;
    	else if (target>nums[j] && target<nums[j+1])
    		return j+1;
    	else {
    	    	i++;
    	    	j--;
    	    
    	}
    }
    return i;

}


posted on 2017-09-26 23:23  sichenzhao  阅读(108)  评论(0编辑  收藏  举报

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