35.Search Insert Position

Given a sorted array and a target value, return the index if the target isfound. 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

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 Array Binary Search

#pragma once
#include<iostream>
using namespace std;

int search(int A[], int begain, int end, int target)
{
	int mid = (begain + end) / 2;
	if (begain == end)
		if (A[begain] < target)
			return begain + 1;
		else
			return begain;
	else if (A[mid] < target)
		return search(A, mid + 1, end, target);
	else if (A[mid] > target)
		return search(A, begain, mid, target);
	else if (A[mid] == target)
		return mid;
}

//法2：二分查找
int searchInsert2(int A[], int n, int target)
{
	return search(A, 0, n - 1, target);
}

//法1：顺序扫描
int searchInsert(int A[], int n, int target)
{
	int result = 0;
	for (int i = n - 1; i >= 0; i--)
		if (A[i] < target)
			return i + 1;
	return result;
}

void main()
{
	system("pause");
}